[jitter] tracking and video projection

hi everybody, forgive my english mistakes, i'm from france.
I started using MAx and jitter in their trial version several days ago..
my project is to video-track from above the movement of an object on a tansparent table .once tracked, i just want to project to the tranlucid panel an image following the movement of the object.thanks to jiter tutorials i've been helped in this tasks, thus i get  two coordinates updating at each frame. 
my problem is that i dont really know how to match to this floating point, the position of another video/image.
sorry, i'm really a newbie... but don't have anyone around me to give me advices..
thanks to anyone that may help me.