@Wilse
On my router, setting up DMZ on a computer is as simple as putting its LAN IP address into a box in the config and saving. From then on, everything on the internet will see this machine and not the router. The only problem of course is if your router doesn't have this feature...
As for bittorrent, it's built into mldonkey. Just type "voo" into the webpage or telnet configuration of mldonkey, and bring up the config. Enable bittorrent there by setting it to TRUE, if not already.
All you need then is to get torrents. Once you find one (google "torrent", you won't need to search much), download it somewhere, go back to where the webpage or telnet, and type "dllink
". i.e. "dllink DH6:foo.torrent". It should now be listed in your downloads and mldonkey will start to download it.
One more thing. If you're only allowed to redirect one port, redirect 6882 and use the bittorrent support. The Donkey network needs two ports opened.