Private Function SearchFile(ByVal sFile As String, ByVal sText As String, _
  ByVal nCDNr As Long, ByVal sLine As String) As Boolean
 
  Dim F As Integer
  Dim bFound As Boolean  
 
  bFound = False
  sText = LCase$(sText)
 
  F = FreeFile
  Open sFile For Input As #F
  While Not EOF(F) And Not bFound
    Line Input #F, sLine
    If Left$(sLine, 8) = "CD Nr. :" Then
      nCDNr = Val(Mid$(sLine, 9))
    Else
      If InStr(LCase$(sLine), sText) > 0 Then
        bFound = True
      End If
    End If
  Wend
  Close #F
 
  SearchFile = bFound
End Function

Dim sFile As String
Dim sText As String
Dim nCDNr As Long
Dim sKunde As String
 
sText = "Karl Mustermann"
sFile = "c:archivDatensicherung.txt"
 
If SearchFile(sFile, sText, nCDNr, sKunde) THen
  MsgBox "CD-Nr.: " & CStr(nCDNr) & vbCrLf & sKunde
End If