Then let us know what idea you have to begin with.
Now, let's get started on working on this script.
on *:text:*:#channel: {
write activeusers.txt $nick
;We've written the user to the list, how do we make sure he's not written there twice and that he gets removed if he doesn't say anything or leaves the channel?
;Hint - /help timers - /help if then else - /help on part
}