Unfortunately, there are no CHDK builds for Canon digital SLR's.
Even if there were, bearing in mind that a time-lapse sequence converted to a movie will playback at 30 images per second, you will need to shoot at a far shorter interval than ten minutes !
Also, do not capture high resolution images, if possible 640x480 or 800x600 or whatever the 400D sizes are will be sufficient.
I think you can buy a plug-in controller for the 400D that has a time-lapse function.
David