Private Sub add_previous_record_Click()
Dim file_mdb As String:           file_mdb = App.Path & "\db1.mdb"

Dim conn As ADODB.Connection:     Set conn = New ADODB.Connection
Dim rst1 As ADODB.Recordset:      Set rst1 = New ADODB.Recordset
 
conn.Provider = "Microsoft.Jet.OLEDB.4.0"   ' Microsoft ActiveX Data Objects 2.7 Library
conn.Open file_mdb, "Admin" ', password

rst1.Open "SELECT * From Таблица " & _
          "ORDER BY Товар, Дата ", _
          conn, adOpenDynamic, adLockOptimistic

Dim price As Double
Dim goods As String

Do While Not rst1.EOF
    
    If rst1![Цена] =  0  Or IsNull(rst1![Цена]) Then

        goods = "" & rst1![Товар]           ' "" - чтобы не бояться пустых значений
    
        rst1.MovePrevious
        
        If goods = rst1![Товар] And Not (rst1![Цена] =  0  Or IsNull(rst1![Цена])) Then
           price = rst1![Цена]
           rst1.MoveNext
           rst1![Цена] = price
        Else
           rst1.MoveNext
        End If
        
    End If
    
    rst1.MoveNext
Loop

rst1.Close:   Set rst1 = Nothing
conn.Close:   Set conn = Nothing
End Sub