<code>Private Sub Command1_Click()
  Dim Von As Date
  Dim Bis As Date
  Dim TT As Integer
  Dim MM As Integer
  Dim JJ As Integer
  Dim sFilename As String
  Dim Summe As Long
  Dim F As Integer
  Dim sLine As String
 
  List1.Clear
 
  <font color=green>' Von und Bis in Datentyp DATE umwandeln</font>
  With Text1
    TT = Val(Left$(.Text, 2)): MM = Val(Mid$(.Text, 4, 2)): JJ = Val(Mid$( _
      .Text, 7))
  End With
  With Text2
    Bis = DateSerial(Val(Mid$(.Text, 7)), Val(Mid$(.Text, 4, 2)), Val(Left$( _
      .Text, 2)))
  End With
 
  Summe = 0
  Do
    Von = DateSerial(JJ, MM, TT)
    If Von > Bis Then Exit Do
 
    <font color=green>' Nur wenn die Datei existiert...</font>
    sFilename = "c:eigene dateien\" & Format$(Von, "dd.mm.yy") & ".txt"
    If Dir$(sFilename, vbNormal) <> "" Then
      <font color=green>' 1. Zeile auslesen und aufsummieren</font>
      F = FreeFile
      Open sFilename For Input As #F
      Line Input #F, sLine
      Close #F
 
      Summe = Summe + CLng(sLine)
    End If
    TT = TT + 1
  Loop
End Sub</code>