Yes, and if you don't know if you're using SSL (and most people don't), just use 6667.
After you connect, the Channels bar comes up. Add #radio to the list, and you can check the little box near the bottom to tell it to automatically join you into that channel (or any other channel you want).
BUT, if you are running 2 copies of mIRC on the same machine (and the same version), by default both copies will join the channel you set, even if you set it on just one. You can change this behavior, but since both copies are feeding from the same Application Data file (Windows), you'll have to save any script to a separate folder, and Reload it each time you start. (you can change this behavior too, I'm not sure how tho)
