http://core.limewire.org/source/brow...-cvsweb-markup
Thanks for the pointer. The code seems to already do what I want. I hadn't actually tried it, because the documentation and the preferences dialog didn't mention that form as a possibility.
So assuming we're both right, then the only real issue is one of documentation.
Now all I have to do is figure out how to test this. Unfortunately, the preferences dialog seems to accept everything - even obviously bogus addresses like 10.1.1.527, so I can't simply enter it and assume it's OK if I don't get an error.