If you are just trying to close a menu which is open, simulate a click on the button which opened it (this will open it if it is closed) or simulate a click on an empty part of the dialog (make sure it's empty so you don't end up clicking another control by accident).
If you really need the handle, you can try
here for a way to get a menu handle for the latest version of Plus!. Please read the post carefully so you understand the limitations and dangers of using this.