Okay, I couldn't figure it out, however I have found an alternative solution for anyone who faces the same issue in the future.
LogMeIn make an awesome, free little VPN client called Hamachi, which adds a virtual network card to your computer, and lets you connect to a regular network (in my case, the android USB tethering) and it's VPN client.
You just create a free account, then create a network and add the required computers to it (up to 5). After you're set up, to browse shared folders of a computer, just right-click it in the Hamachi window and select 'Browse'. Works like a charm, and is a more than acceptable workaround.