Option Explicit 

Dim Abbruch As Boolean 

 

Private Sub Command1_Click() 

  Abbruch = True 

End Sub 

 

Private Sub CopyDir() 

  Abbruch = False 

  For i = 0 To 999 

    FileCopy ... 

    DoEvents 

    If Abbruch Then Exit For 

  Next i 

  If Abbruch Then MsgBox "Vorgang abgebrochen" 

End Sub