Code:
on me:*:JOIN:#:{
  set %join $+ # 1
}
raw 366:*:{
  if ( $eval(% $+ join $+ $2,2) ) {
    savenicks $2
    unset %join $+ $2
  }
}
alias savenicks {
  var %i = 1
  while ( $nick($1,%i) ) {
    write nicks.txt $ifmatch
    inc %i
  }
}
  


add these to a new script file...