Mounting GMA files into Source engine's filesystem

1
I have a GMod-style Source engine mod that mounts assets from other games. It works great with all games of the same engine branch EXCEPT for GMod, because GMod addons are packed into GMA files.

Is it possible to mount GMA files into the Source engine file system as if they were a regular folder/VPK?

I'm using the git for GMAD as a guide for how GMA files work:
https://github.com/garrynewman/gmad/blo ... onReader.h

It seems like reading files from the GMA would be possible, but I'm unsure how (or if it's even possible) to combine that with the Source engine file system so that the assets can be normally used in-game.

Does anybody have some insight they could offer me on this subject before I delve in?

Thanks.