I don't want to spoil everything, but in addition to the IP/hostname you will need the port number and that is not always 6346.

And while browsing leafs won't be a problem, browsing ultrapeers probably won't work very well. At the moment LimeWire ultrapeers are so overloaded that seem to answer to about 20% of all incoming tcp connection attempts, the rest will either timeout or be refused (running as an ultrapeer is almost like a tcp syn flood denial of service attack).

I investigated when I noticed that if running as an ultrapeer (although illegaly sharing a couple of thousand copyrighted songs) I would have close to no uploads.