Transformations with ofNode and ofEasyCam

Hi all !, I'm trying to understand what's happening with ofEasyCam and ofNode transformations.

I have a class X which extends ofNode, with an instance Z and set up my ofEasyCam as it's parent.

After playing a little with the camera, i want to check if the mouse is inside some rectangle of my instance Z.

How can i do that?

Also, can you point me to some good tutorial or book that explains this?

Thanks !!