Attribute VB_Name = "Modul1"
Sub hole_neue_nr()
Dim nRechNr As Long
nRechNr = GetNewNumber("lfdNr.dat")
If nRechNr < 0 Then Exit Sub
ActiveCell = nRechNr
End Sub

Sub hole_alte_nr()
Dim nRechNr As Long
nRechNr = GetLastNumber("lfdNr.dat")
If nRechNr < 0 Then Exit Sub
ActiveCell = nRechNr
End Sub

Sub setze_neue_nr()
Dim nRechNr As Long
nRechNr = SetNumber("lfdNr.dat")
If nRechNr < 0 Then Exit Sub
ActiveCell = nRechNr
End Sub


Public Function GetNewNumber(dateiname As String) As Long
    Dim lFileNr         As Long
    Dim lNr             As Long
    Dim tFN             As String

    On Error GoTo ErrorHandler

    tFN = ThisWorkbook.Path & "\" & dateiname
    lFileNr = FreeFile

    Open tFN For Random As #lFileNr
        If EOF(lFileNr) = False Then
            Get #lFileNr, 1, lNr
        End If
        lNr = lNr + 1
        Put #lFileNr, 1, lNr
    Close #lFileNr

    GetNewNumber = lNr
    Exit Function

ErrorHandler:
    GetNewNummer = -1
End Function

Public Function GetLastNumber(dateiname As String) As Long
    Dim lFileNr         As Long
    Dim lNr             As Long
    Dim tFN             As String

    On Error GoTo ErrorHandler

    tFN = ThisWorkbook.Path & "\" & dateiname
    lFileNr = FreeFile

    Open tFN For Random As #lFileNr
        If EOF(lFileNr) = False Then
            Get #lFileNr, 1, lNr
        End If
    Close #lFileNr

    GetLastNumber = lNr
    Exit Function

ErrorHandler:
    GetLastNummer = -1
End Function

Public Function SetNumber(dateiname As String) As Long
    Dim lFileNr         As Long
    Dim lNr             As Long
    Dim tFN             As String

    On Error GoTo ErrorHandler

    tFN = ThisWorkbook.Path & "\" & dateiname
    lFileNr = FreeFile

    Open tFN For Random As #lFileNr
        lNr = CLng(ActiveCell)
        Put #lFileNr, 1, lNr
    Close #lFileNr

    SetNumber = lNr
    Exit Function

ErrorHandler:
    setNummer = -1
End Function