program to automatically play quicktime and screensaver

I apologize if this forum has been posted and I know similiar ones have, but not this specific so i thought i would give it a try.

I am looking for a program or a way to have my Mac (running snow leopard) automatically play a quicktime video file in full screen mode at certain times of the day set by me on certain days. After the movie is done, I need it to go to the slideshow screensaver that is set up and stay that way until the timer goes off again for quicktime.

Anybody have suggestions or ideas on a program or how to write that script. Thank you