Option Explicit

Function MaxDirLen(ByVal Pfad As String, ByVal MaxSize _
      As Integer) As String

  Dim i As Integer, pLen As Long

  pLen = Len(Pfad)
  MaxDirLen = Pfad
  If MaxSize = 0 Then MaxSize = 20
  If Len(Pfad) <= MaxSize Then Exit Function

  For i = pLen - MaxSize + 6 To pLen
    If Mid$(Pfad, i, 1) = "\" Then Exit For
  Next i

  MaxDirLen = Left$(Pfad, 3) & "..." & Right(Pfad, pLen - (i - 1))
End Function

MsgBox MaxDirLen("c:\windows\system\test.txt", 25)