Code:
 
on @!*:join:#: {
  var %host_to_search_for = $address($nick,2)
  var %number_from_that_host = $ialchan(%host_to_search_for,$chan,0)
  if (%number_from_that_host > 1) {
    ;we have clones!
    ;first set up our vars and loop
    var %count = 0
    unset %clones
    :loop
    inc %count
    ;loop through every nick, adding the nicks to %clones
    var %clones = %clones $ialchan(%host_to_search_for,$chan,%count).nick
    if (%count < %number_from_that_host) { goto loop }
    msg $chan (Clones) %count clones from $address($nick,2) %clones
  }
}