i maked an alias to test it and it works fine here, i get the nicklist sorted exact like in mirc


Code:
 
when you open a channel window for the first time thoes switch must be include  -l15Sk0 

alias -l nicklist {
  var %a = $0
  while (%a) {
    aline -ln %chan $gettok($1-,%a,32)
    dec %a
  }
}
raw 353:*:{ 
  set %chan $+(@,$3)
  nicklist $gettok($6-,1,58) 
}


Note use aline -ln not just only aline -l (-n) switch is used to prevent a line from being added if it exists.