Code:
on *:NICK: { 
  if ($hget(badnick,$newnick)) {
    var %n = $comchan($newnick,0)
    while (%n) { if ($me isop $comchan($newnick,%n)) {
        ban -k $comchan($newnick,%n) $newnick 2 please change nick (forbidden nick)
      }
      dec %n
    }
  }
}
on *:START:if (!$hget(badnick)) hmake badnick 100
on *:PART:hsave -o badnick badnick.hsh
on *:DISCONNECT:hsave -o badnick badnick.hsh

So basically you just enter:
Code:
/hadd -m badnick <badnick here> 1
to add a bad nick. Then every time someone matches a bad nick you've added in the hash tables, he or she will be kicked and banned upon a nick change.