Someone

alias ss {
  var %k = 1
  while (%k <= $nick($chan,0)) {
    if (*ss* iswm $left($address($nick($chan,%k),1),5)) {
      inc %ss
      inc %k
    }
    else {
      inc %mirc
      inc %k
    }
  }
  say mIRC users: %mirc $+ , SS users: %ss $+ . | unset %mirc | unset %ss
}