Although i am not familiar with the device..
Here what you can do, plug in the device open windows 7 device manager and then check if there is any unknown device listed. If you find one, that means you need to install a driver
. But you dont have one. i think the driver is included in that software for the device.
I think what is happening is that the software for the device is installed in the guest os(xp) but it is not installed on the host os(Windows 7) that is the reason that device is not provided to the guest os(xp).
You need the driver. I think you will get it in
"Windows xp drive(in VM)\windows\system32". Copy two folder named as "Drive store" and "Drivers
" and past it in any drive in your physical machine. Now open device manager of windows 7 right click the unknow device and click "update driver" now click "browse my computer for driver software". Then chose one of those folder and let it search and if driver is not found then again chose the other folder.
O i forgot to tell you welcome to sevenforums..
Hope this will work....
Best of luck...