Static camera animation

[u4ia]

I'm trying to get my head around this problem.

Scenario:
I have a model of a building with three static cameras at different angles.
The client wants an animation of each with the camera in a static position. The parts that get animated are all material animations and consists of signage panels in a mix of video panels, Rotovision scroller signage and rolling signage. If time permits I'd like to animate a car going by etc, but that's if I have time.

My question is the following: I assume it possible to use Premiere to layer different parts of the animation since the foreground won't change. Is there a way to render a single alpha masked still of the foreground and overlay it over the changing building? Even better - can I render 2 stills (one foreground and one building) and then the animation of the signage panels and merge this in Premiere? I don't have combustion so that's not going to help me.

Thanks

[Dynedain]

Theoretically it is possible, it's all dependent on how sophisticated the tools are in premiere.

Most of these things are easier in Combustion, because it is designed to be a compositing program that happens to have some editing capabilities, whereas premiere is a editing program that has some rudimentary compositing functionality.

[u4ia]

I'm assuming that I'd have to composite everything, but I'm open to suggestions...

What I've tried and it seems to be a part solution is to render the first frame and save it. Using region rendering one can limit to an extent what gets rerendered. As long as it's done on only one pc it's fine, but I don't know if I can region render an animation via backburner since it won't keep the previous image in memory.

Using shadow/matte material will imply I'd need to composite again.

Edit: If I have to composite, what other program apart from Combustion will do the trick?