Function ShellAndWait(ByVal sPath As String, ByVal winStyle As VbAppWinStyle, Optional sTiempo As Long) As Boolean powerbuilder

como seria la declaracon de la funcion Function ShellAndWait(ByVal sPath As String, ByVal winStyle As VbAppWinStyle, Optional sTiempo As Long) As Boolean  en power builder ya que utiliza "winStyle As VbAppWinStyle, Optional sTiempo As Long" como tipo de datos