GAP - Add new layer to all frames

[maestro]

I am trying to merge two videos. One with a background, and one with a foreground obtained using the bluebox feature. I would like to merge 381 foreground frames (with transparency) over the top of 381 background frames to generate 381 composite frames with both the foreground and background animated.

I have so far only found a way to use the "move path" feature merge my 381 foreground frames with a single background frame (which gives a similar effect, except that the background is static).

Is there a way to merge the two sets of video frames?


Thanx