Sadly its not a PCI card, both are AGPs. But I cant image that this simply is impossible.
If u think about it, it's not that hard. It would only need a server program simulating a graphics adapter on the Host system, while the client receives the information and displays it.
I heard of USB to VGA adapters which do exactly this except they dont need a client system. So simulating a graphics card is possible.

Anyone knows more?