I can try that, but I'm betting that it isn't as easy to change a config file to get the microsoft vm to work for the same reason you are mentioning...idiot proofing etc. I looked through a few pages of google searches and couldn't find alot relating to it, but more may be available in the technet boards/blog etc.
I fooled a bit more with this issue, I had a older a4tech wop-35pu dual mouse, this mouse will not install under windows 7, but it would install under the virtual xp mode. Driver went all the way through and even loaded it's icon in the taskbar so alot better install than the other mouse. I can right click the mouse icon in the taskbar and pull up the mouse driver properties and set all settings and they take and the option is saved. Now for the bad...with all of this still the scrolling wheels do not work under autocad. For some reason both wheels only zoom. It is weird, some of the mouse features work, like there is a goofy sonar feature that will put a circle around the mouse pointer if you hit cntrl key etc. even that worked, but other things such as mouse tails for instance and the scrolling do not. So the vm is giving that driver a partial control at best. It is infuriating to be so close and part of it to work and not that. I will test some more and see if the scrolling function works on other programs such as internet pages or office or wordpad etc