Thanks for the info Uhrwerk.

@Lukas: Don't worry, I'm in no hurry for that feature. By the way, what is an Abitur?

And another question:
How do I detect if the cursor is over any LBGUI object?
I found LBG_mouse_over_object(LBG_WINDOW* obj) in the manual, but that only checks a window I send as parameter.
Is there any way to know if it is on any object?
(What I am trying to do is stop other "click-related" things that happen in my game when the cursor is over any LBGUI object.)