Joins all the channel when you type /joinall
You have do /list then save the list as a file in your mirc dir, which you you can find out by doing, then save it as list.txt

//echo -a $mircdir

WARNING! THIS MAY CAUSE MIRC TO CRASH ON BIG NETWORKS!
You are using this script at your own risk!

; Copyright MartyniP
; irc.geekshed.net #martyni 
; irc.windfyre.net

alias joinall {
  if ($isfile(list.txt) != $true) {
    echo -t 11* Please save the /list as in your mirc dir and save as list.txt
    echo -t 11* The /list will automaticly load soon
    .timer01 1 5 list
    halt
  }
  if ($isfile(list.txt) == $true) {
    %lines = $lines(list.txt)
    %done = 2
    while (%done != %lines) {
      %chan = $read(list.txt, %done)
      %chan = $gettok(%chan,1,32)
      .join %chan
      .inc %done
      .unset %chan
    }
    .unset %chan
  }
}