Something

alias hpbar {
  if ($2 !isnum) {
    return
  }
  if ($2 < 5) {
    return 4,4.........1,4 $+ $2 $+ 4,4..........
    halt
  }
  var %i = $calc($2 /5)
  var %d = 9,9 $+ $str(.,%i) $+ 4,4 $+ $str(.,$calc(20 - %i))
  return $replacecs($remove(%d,$chr(3),4,9),$mid($remove(%d,$chr(3),4,9),10,1),$2)
}