hope it is possible, im only trying to manipulate one window (width / 2 )
WoW did allow me to do this using an addon that worked much like the assetids, only it had one for the renderwindow, so it could be halfed (placed onto one screen)
as for how to use dual monitors i use catalyst to stretch a single display onto 2 monitors.
LOTRO works like this, only my player is half one screen, half the other.
Using the displays smarter would be the whole aim of this task..
someone please tell me about assetid screenX , screenY and il love ya!