Public Function TextSearch(ByVal strText As String, _  
ByVal strSuch As String, _  
Optional ByVal bCase As Boolean = False, _  
Optional ByVal lBegPos As Long = 1) As Long   
Dim lPos As Long    
 
   If lPos < 1 Then lPos = 1  
      If bCase Then    ' Groß-/Kleinschreibung beachten!    
           lPos = InStr(Mid$(strText, lBegPos), strSuch)  
    Else    ' Groß-/Kleinschreibung ignorieren!    
           lPos = InStr(LCase$(Mid$(strText, lBegPos)), _      
           LCase$(strSuch))  
    End If  
 
    TextSearch = lPos
 
End Function

rZF1 = TextSearch(Route, "ZF1")