If you want players to have same names on your server as on irc channel then there is other way:
You can create irc bot with amxx, so when you start the server, amxx irc bot will connect to your irc channel and when player connects to server, then bot will check if there is user on irc with same ip and change player name to irc name if user with same ip was found.
Coding such plugin would take me some time and I don't really feel like doing it right now (I have some other plugins to code). If you can't do it yourself then post in suggestion/requests instead of scripting help.