https://trac.torproject.org/projects/tor/wiki/doc/TorifyHOWTO/XChat#HexChatWindowsUnix might get you closer
man, that wiki page is not as useful as it could be
"you can configure your irc client to use the tor client that's included in tor browser. just set your socks5 proxy to localhost port 9150."
that should get you started. it doesn't cover all the more complicated things, like how you might want to use encryption between your irc client and the irc network (you should want to do this even if you're not using tor)