How Drawmenu work's?

[fabio.hdl]

First of all Hello to everybody, i'm new in this forum!
If i'm posting this in the wrong place, since here is my apology.

Well, i'm having some trouble with HP PPL, more especifically with DRAWMENU command, i want to know how i handle with it, I managed to draw the menu but i don't know how to interact with it.
My question is, do the HP PPL have a command to menu events? Like ISKEYDOWN();?
Or i'll have to make a MOUSE event to know the coordenate of the menu?

Again, i'm sorry if this question has already been answered, like i said i'm new here!