Something

alias voiceall {
  if (($me isop $active) || ($me ishop $active)) {
    set %x $nick($active,0)
    while (%x > 0) {
      dec %x      
      inc %y
      if ($nick($active,%y) isreg $active) {
        mode $chan +v $nick($active,%y)
      }
    }
    unset %x
    unset %y
  }
}

alias devoiceall {
  if (($me isop $active) || ($me ishop $active)) {
    set %x $nick($active,0)
    while (%x > 0) {
      dec %x
      inc %y
      if ($nick($active,%y) isvoice $active) {
        mode $chan -v $nick($active,%y)
      }
    }
    unset %x
    unset %y
  }
}