My guess would be that you need to write drivers if it can't emulate a card that you have drivers for. Another way is to buy a 802.11 bridge (no drivers needed).
I was not aware of this product. I had thought to purchase a wireless router which had ethernet ports as well but this wouldn't allow me to move the pegasos anywhere in the house. it would mean I would have to move the router as well. I think this wireless bridge will solve my problem better.