mod only addcom? it is already mod only. I think you mean so that only mods can use it. In which case, I think I would make it specific commands (because it's way easier and let's face it, how many mod only commands will you need?). It would look like:
on *:TEXT:!modonly:#: {
if($nick isop #){
msg # This command can only be executed by a mod.
}
else {
msg # You can't use this command.
}
}
To be honest, I would read the forums and see how I can do that. It really isn't that hard. I made my own bot and besides the point system that I got from youtube, everything else I got from the forums and now my bot has a point system, raid command, add commands, polls, script that choses the user with most points and gives him mod, giveaway system based on points and many more...