Well you could setup just a remote desktop connection with an FTP client running on your computer so you can access it from the road. But what a VPN does is creates a virtual link between your computer and you (virtual private network). It essentially tricks your computer into thinking that you are on the same network (subnet) as the other computer connected to a private network. I know a program like hamachi (not sure on the spelling) does VPNs so you might try playing with that.