I do not have mine setup here but yes you can go into your router and I think it is under advanced setting and may be called 'port forwarding' so that when you set a port and name for the service and point it to whatever IP on your local network you want to point the request to.
I use a program called realvnc that works great and use it on an almost daily basis and on the server side (the pc your are dialing into) it seems to have much better stability than I had with pcanywhere or netmetting, just a thought.
also it is free if you have not already thrown down the cash for PCA