Private Const FILE_BEGIN = 0
Declare Function SetFilePointer Lib "kernel32.dll" (ByVal hFile As Long, ByVal _
  lDistanceToMove As Long, ByRef lpDistanceToMoveHigh As Long, ByVal _
  dwMoveMethod As Long) As Long
 
Sub SelectSector(adress As Long)
'Wählt den zu beschreibenden oder zu lesenden Sektor aus
    adress = adress * 512
    If CreateFileError Then
        ReadFileError = 1
        Exit Sub
    End If
    retReadFile& = SetFilePointer(lngFileHandle, adress, FILE_BEGIN, 0&)
    If retReadFile& = 0 Then
        MsgBox "Readfile returns " & Str$(retReadFile&) & vbCrLf & "Read Error!"
        ReadFileError = 1
        Exit Sub
    End If
End Sub

Private Sub Command7_Click()
  Dim adress As Long
  adress = Text2.Text
  SelectSector adress
End Sub

Zitat:

lpReOpenBuff Erwartet eine "OFSTRUCT"-Struktur die mit Informationen zu der geöffneten Datei gefüllt wird.