Turn off printing status dialog with Excel automation

[gm]

Does anyone know how to turn off the printing status dialog, which is
displayed when printing a sheet with excel via automation?

By using this code, there is always displayed a print status dialog, while
excel is printing the document.

app.CreateDispatch("Excel.Application");
app.SetVisible(FALSE);
app.SetDisplayAlerts(FALSE);

workbooks = app.GetWorkbooks();
workbook = workbooks.Open(.....);
workbook.PrintOut(vOpt, vOpt, vOpt, vOpt, cstrPrinter, vOpt, vOpt);

Thanks for help
gm