Code:
on *:text:!stats *:#:{ 
  if ($isfile($2-.txt)) { msg # $read($2-.txt,nt,1) }
  else { msg # $qt($2-) invalid champion. }
}


If there is going to be a different level on each line in the file, and you want to be able to specify the level number but have it default to one, then this should do that:

Code:
on *:text:!stats *:#:{ 
  var %level = 1, %champion = $2-
  if ($eval($ $+ $0,2) isnum) { 
    %level = $v1 
    %champion = $deltok($2-,-1,32)
  }
  if ($isfile(%champion $+ .txt)) { msg # $read(%champion $+ .txt,nt,%level) }
  else { msg # $qt(%champion) invalid champion. }
}


You can see where the mIRC directory is by typing "/run ." in mIRC.