Code:
On @*:Join:#: {
  set -u15 %bad.chans $chan
  .enable #badchans  
  whois $nick
}

#badchans off
Raw 319:*: {
  if (($numtok($3-,31) >= 20)) && ($me isop %bad.chans)) { ban -k %bad.chans $2 2 Goodbye. }
  .disable #badchans
}
#badchans end


Don't know if this is what you wanted, I didn't really understand what you asked for..

-Andy