Mac Serial to PC - keyspan drivers and others?

I got the Keyspan Mac serial to USB adapter (USA-28) because I want to connect a Wacom Graphics Tablet with a mac serial connector to my PC and it's the only product I've seen so for that will connect to a legacy mac product to USB. After I got the adapter I found out that I need a driver for it and Keyspan doen't have any or support any windows drivers for it.

So has anyone else had this problem? How did you get around it?

Maybe you may know of another product that will do the same or a better job?

Otherwise, I'm thinking of writing a decive driver for it. I know some programing but not a lot. So would someone or an opensource group be willing to aid me in writing a driver?