As far as I know it doesn't accept the spaces inside the brackets. But you can manipulate them. In your text file, make it like this:
Quote:
[question_one_here]
Then the code like so:
Code:
on *:TEXT:!faq *:#MY_CHAN:{
  var %f = file.txt, %x = $replace($2-,$chr(32),_)
  if ($isfile(%f)) && ($read(%f,nw,$+([,%x,]))) {
    .play $+(-t,%x) # %f
  }
}
The user can then enter command as usual with spaces:
Quote:
!faq question one here
What happens is that the $replace identifier will change all the spaces to underscores, which will then match with the topics exactly.