hope it gives you fun ;-) , anno your much deeper into poser then I ever was lol so anything I find that might bridge that gap I will pass on for you

dunno if you do movies but saw this an knew you had PS (no good to me blenders compositer is pushing gimp out the window lol)

http://www.photoshopgreenscreen.com/

is a free one and a trial for paid one

ps if you get Hedd ache just tell me to get lost for a while ;-)