um no need for the set var as well no need for the timer

on $@*:TEXT:/^@ban\s(\S+)\s(\d+)$/iS:# {
  if ($nick isop # && $regml(1) ison #) { ban $+(-u,$regml(2)) # $regml(1) 5 }
  else { msg # permission denied. }
}

or

on $@*:TEXT:/^@ban/iS:# {
  if ($nick isop # && $2 ison #) { ban $+(-u,$3) # $2 5 }
  else { msg # permission denied. }
}