If the Dell is not connected to the hub and you can share files then that is great (half way there)and they can see each other(not just one way) which is also great. Just to be sure I have it clear. The systemacvpc is connected via cable to the hub and the dell is still wireless. We don't need to connect the dell to the hub then. If this is correct then I think the next step is to see if we can get the virtual machine to connect via wirless. If this works then we know that we should be able to do it via the real pc. How does this sound to you.
If all of this is correct then start the virtual pc and make a restore point then shut down virtalpc and real pc. Unplug the cable from the hub and computer. Start the pc and virtual pc and plug in the dongle. Does virtual pc pick it up. If yes do an ipconfig and try file sharing.