Sub SaveToPdf()
    Dim oDisp, oFrame
    Dim a(2) As New com.sun.star.beans.PropertyValue
    a(0).Name = "URL"        : a(0).Value = "file:///c:/temp/my_file_name_.pdf"
    a(1).Name = "FilterName" : a(1).Value = "writer_pdf_Export"
    oFrame = ThisComponent.CurrentController.Frame
    oDisp = createUnoService("com.sun.star.frame.DispatchHelper")
    oDisp.executeDispatch(oFrame, ".uno:ExportDirectToPDF", "", 0, a())
End Sub