non-hardware device driver?

I have a device driver that talks to a PCI bus DAQ card and uses some
kernel calls to manipulate memory buffers I set up in the area above
the /MAXMEM= boot parameter.

I want to use the driver under XP for some simulator user code that
runs on systems without the DAQ card present. (i.e., to still access
the driver calls to manipulate buffers in area above MAXMEM.)

Under NT/2000, I would have put a flag "UseHardware=0" in the registry
to tell the driver not to talk to the hardware but I could have still
started the driver using "net start mydriver".

Under XP with PNP and .inf files, how can I do this?
In other words, how can I get XP to load my driver with no
vendor/device ID on the bus and, if I can get it to call DriverEntry(),
how do I get it to call AddDevice() which is where all my setup code
lives?

Thanks.

--Ed