Norton Firewall Warning

The script kiddy mode applies only if you won't spend time to learn how the tools you download acctualy do their job.

If that's the way you want to go you should remember that any "abnormal" activity intentionaly directed from and/or towards a machine you do not own, or have not been granted a permission if you do not, is illegal. In some cases it might cause you problems to simply use a network (the internet, or at least a part of it that belongs to an ISP, etc...), even though you have the appropiate rights for both machines. That is why I strongly suggest you build your own network to experiment on.

Having said that, make a search for a trojan server and client...install the trojan server on the target machine and the client on your own...tunnel the connection trough a firewall(if any) and that's about it. (the short, undescriptive version you could learn anywhere on the internet). A word of warning regarding trojan clients, their makers usualy include a small server into them so that they may connect to them the same way you connect to the server on the target machine. But that shouldn't make a difference if you isolate the sandbox network from the rest of the internet.