Private cnn As New ADODB.Connection

Private Sub ComboBox6_Change()
    Dim strSQL As String
    
    strSQL = "SELECT Column7 " _
      & "FROM tblPrice " _
      & "WHERE Column1='" & Me.ComboBox1 & "' AND " _
      & "Column2='" & Me.ComboBox2 & "' AND " _
      & "Column3='" & Me.ComboBox3 & "' AND " _
      & "Column4='" & Me.ComboBox4 & "' AND " _
      & "Column5='" & Me.ComboBox5 & "' AND " _
      & "Column6='" & Me.ComboBox6 & "'"
    
    Me.TextBox7 = fnSqlLookup(strSQL)
End Sub

Private Sub UserForm_Activate()
    Dim rst As New ADODB.Recordset
    
    cnn.Open "Provider=Microsoft.Jet.OLEDB.4.0;" _
      & "Data Source=D:\My Databases\dbTest.mdb;" _
      & "Persist Security Info=False"
    
    rst.Open "tblPrice", cnn, adOpenStatic, adLockOptimistic, adCmdTable
    
    Do Until rst.EOF
        Me.ComboBox1.AddItem rst!Column1
        Me.ComboBox2.AddItem rst!Column2
        Me.ComboBox3.AddItem rst!Column3
        Me.ComboBox4.AddItem rst!Column4
        Me.ComboBox5.AddItem rst!Column5
        Me.ComboBox6.AddItem rst!Column6
        rst.MoveNext
    Loop
    
    rst.Close
    Set rst = Nothing
End Sub

Private Function fnSqlLookup( _
  strSQL As String) As Variant
    Dim avarArray As Variant
    
    On Error GoTo HandleError
    
    avarArray = cnn.Execute(strSQL).GetRows
    
    fnSqlLookup = avarArray( 0 ,  0 )

ExitHere:
    Exit Function
HandleError:
    Select Case Err.Number
        Case  3021 
            fnSqlLookup = "Такой записи нет!"
        Case Else
            MsgBox Err.Number & " : " & Err.Description
            Resume ExitHere
    End Select
End Function