Dim oExcel As Object = Nothing
        Dim oBook As Object = Nothing
        Dim oSheet As Object = Nothing
 
        'Arbeitsmappe öffnen:
        oExcel = CreateObject("Excel.Application")
        oBook = oExcel.Workbooks.Open("C:\Temp\Mappe4.xlsx")
        oSheet = oBook.Worksheets(1)
        'Zeilennummer nach der letzten Zeile bestimmen:
        Dim Zeile As Integer = oSheet.UsedRange.Rows.Count + 1
 
        'Daten in neue Zeile einfügen:
        oSheet.Range("A" & Zeile).Value = "Test"
 
        oBook.Save("C:\Temp\Mappe4.xlsx")
        oSheet = Nothing
        oBook = Nothing
        oExcel.Quit()
        oExcel = Nothing
        GC.Collect()