Dim masFile() As Byte
Open inpFile For Binary Access Read Lock Read As #inpFree
rSize = LOF(inpFree)
	
ReDim masFile(  0  To ? )

Do While rSize > ???
     Get #inpFree, , masFile()
     тут работаете с masFile()
Loop
	
Close #inpFree

Private Sub Command1_Click()
    variant2 App.Path & "\file.log", "искомое слово"
End Sub

Private Sub variant2(FileLog As String, FindWord As String)
Dim LenWord As Integer, KB As Integer, k2 As Integer, bt As Double
Dim masFind() As Byte
Dim masFile() As Byte
Dim rSize As Double, i As Integer, j As Integer, f As Integer, k As Integer, k1 As Byte

Dim time1 As String:                    time1 = Format(Time(), "Long Time")

For i =  1  To Len(FindWord)              'перевод искомого слова в массив кодов
    ReDim Preserve masFind( 0  To i -  1 )
    masFind(i -  1 ) = Asc(Mid(FindWord, i,  1 ))
Next
LenWord = UBound(masFind)

Dim inpFree As Integer
    inpFree = FreeFile

Open FileLog For Binary Access Read Lock Read As #inpFree

k1 =  0                                   'определимся, какими частями будем читать
bt =  0 
KB =  1024 
rSize = LOF(inpFree)
If rSize < KB Then
    KB = rSize
End If

Do While rSize > bt
    bt = bt + KB
    If k1 =  0  Then
        ReDim masFile( 0  To KB)
        k1 =  1                           'читаем первую часть
        k2 = KB
    Else
        ReDim Preserve masFile( 0  To (KB + KB))
        k1 =  0                           'читаем вторую часть сохраняя первую на тот случай,
        k2 = KB + KB                    'если искомое слово оказалось на стыке двух частей
    End If
    Get #inpFree, , masFile()
    
    f = - 1                               'обыкновенный поиск в массиве, "перебором"
    k = - 1 
    For i =  0  To LenWord
        For j = f +  1  To k2
            If masFind(i) = masFile(j) Then
                f = j
                k = k +  1 
                Exit For
            End If
        Next
        If f = - 1  Then Exit For
    Next
    If k = LenWord Then Exit Do
    
Loop
 
Close #inpFree

MsgBox time1 & vbCrLf & Format(Time(), "Long Time")

If k = LenWord Then                     'здесь что-нибудь сообщаем
    stroka = ""
    For i = f - k To f
        stroka = stroka + Chr(masFile(i))
    Next
    MsgBox stroka
Else
    MsgBox "не найдено"
End If

End Sub

Private Sub variant2(FileLog As String, FindWord As String)
Dim LenWord As Integer, KB As Integer, k2 As Integer, bt As Double
Dim masFind() As Byte
Dim masFile() As Byte
Dim rSize As Double, i As Integer, j As Integer, f As Integer, k As Integer, k1 As Byte

For i =  1  To Len(FindWord)              'перевод искомого слова в массив кодов
    ReDim Preserve masFind( 0  To i -  1 )
    masFind(i -  1 ) = Asc(Mid(FindWord, i,  1 ))
Next
LenWord = UBound(masFind)

Dim inpFree As Integer
    inpFree = FreeFile

Open FileLog For Binary Access Read Lock Read As #inpFree

k1 =  0                                   'определимся, какими частями будем читать
bt =  0 
KB =  1024 
rSize = LOF(inpFree)
If rSize < KB Then
    KB = rSize
End If

Do While rSize > bt
    bt = bt + KB
    If k1 =  0  Then
        ReDim masFile( 0  To KB)
        k1 =  1                           'читаем первую часть
        k2 = KB
    Else
        ReDim Preserve masFile( 0  To (KB + KB))
        k1 =  0                           'читаем вторую часть сохраняя первую на тот случай,
        k2 = KB + KB                    'если искомое слово оказалось на стыке двух частей
    End If
    Get #inpFree, , masFile()
    
    f = - 1                               'обыкновенный поиск в массиве, "перебором"
    k = - 1 
    For i =  0  To LenWord
        For j = f +  1  To k2
            If masFind(i) = masFile(j) Then
                f = j
                k = k +  1 
                Exit For
            End If
        Next
        If f = - 1  Then Exit For
    Next
    If k = LenWord Then Exit Do
    
Loop
 
Close #inpFree

Dim LineBefore As String
Dim Line_After As String
Dim FindBefore As Integer

If k = LenWord Then
    LineBefore = ""                     'найдём строку от найденного, вверх по тексту
    FindBefore = - 1 
    For i = f - k To LBound(masFile) Step - 1 
        If masFile(i) =  13  Or masFile(i) =  10  Then
            FindBefore = i
            Exit For
        End If
    Next
    If FindBefore > - 1  Then
        For i = FindBefore +  1  To f - k -  1 
            LineBefore = LineBefore & Chr(masFile(i))
        Next
    End If
    Line_After = ""                     'найдём строку от найденного, вниз по тексту
    For i = f - k To UBound(masFile)
        If masFile(i) =  13  Or masFile(i) =  10  Then Exit For
        Line_After = Line_After & Chr(masFile(i))
    Next
    MsgBox LineBefore & Line_After
Else
    MsgBox "не найдено"
End If

End Sub

Do While rSize > bt
    bt = bt + KB
    ReDim masFile( 0  To KB)
    Get #inpFree, , masFile()
    
    f = - 1                               'обыкновенный поиск в массиве, "перебором"
    k = - 1 
    For i =  0  To LenWord
        For j = f +  1  To KB
            If masFile(j) <>  13  And masFile(j) <>  10  Then 'пропускаем vbCrLf
                If masFind(i) = masFile(j) Then
                    f = j
                    k = k +  1 
                    Exit For
                End If
            Else
                If k < LenWord Then
                   k = - 1 
                End If
            End If
        Next
        If f = - 1  Then Exit For
    Next
    If k = LenWord Then Exit Do
Loop
Close #inpFree

Schema.ini
[mylog.txt]
ColNameHeader = False
Format = TabDelimited
CharacterSet = ANSI
MaxScanRows =  0 
Col1 = Action Text

Private Sub Command1_Click()
    Dim ConnectionString As String
    Dim cn As ADODB.Connection
    Dim rs As ADODB.Recordset
    
    ConnectionString = "Driver={Microsoft Text Driver (*.txt; *.csv)};" & _
                       "DriverId=27;FIL=text;MaxBufferSize=2048;" & _
                       "PageTimeout=5;Extensions=txt;log" & _
                       "DBQ=C:\TMP\;DefaultDir=C:\TMP;"
                       
    Set cn = New ADODB.Connection
    cn.Open ConnectionString
    
    Set rs = New ADODB.Recordset
    Set rs.ActiveConnection = cn
    
    Dim SQL As String
    SQL = "SELECT * FROM [mylog.txt] WHERE Action LIKE '*искомое слово*'"
    
    rs.Open SQL, , , , adCmdText
    
    Do While Not rs.EOF
        Debug.Print rs!Action
        rs.MoveNext
    Loop

    rs.Close:   Set rs = Nothing
    cn.Close:   Set cn = Nothing
End Sub