There are a number of scripts that already do this. Try checking
Hawkee and/or
mIRC.Net with a search for Statistics.
For promotional purposes, you might want to think about registering the room with
Search IRC If you are unable to find a script that you like on one of those sites (or a site that has a link from those sites), let me know and I'll see what I can do after Tuesday when my DSL is scheduiled to be back up & running.