Making using multiple movie clips

[BlueGeek]

I'm working on a project where in I've found it necessary to mask a background object with MULTIPLE Sprites. I've tried doing this two ways: making one "parent" sprite to which all of the other masks are childed; adding them as individual masks.

The composite strategy just sort of gave up, Flash doesn't seem to like having to search through it's render tree to do these things and the result was no visible mask or masking (just the full background image). The latter strategy failed for obvious reasons: saying Sprite.mask = so-and-so implies that setting it again will overwrite the last mask.

Is there any way to use the composite strategy? Or is there a way I can copy over all of my sprites and draw them directly into one new sprite on every frame?

thanks,

-Sandy