Indeed you can. I don't use Trillian anymore, but in Gaim, you go to Tools, then Accounts. Click Add, then choose IRC from the protocol box. Then you fill in your screen name, an efnet server (irc.choopa.net, for example), your alias and any of the other options you want to set. After that, connect with the accounts dialog, then in the main window, click buddies, join a chat, choose your IRC connection and enter #donationcoder in the channel box. Easy, no?