Mix Two Z-depths?

[rifz]

Can you mix two images with z-depths? I've rendered an images of pipes and another of racking (.RLA in maya 8). The pipes are intertwined with the racking that holds them up. Since both images have z-depths can I put them together in AfterEffects 7pro so they look correct? is that possible with z-depth? how would I do that?

The reason is that I would like to use a wipe effect to animate the pipes growing through the racking.

thanks!