You can do it like this.
!insult[nr] [nick]

On *:TEXT:!insult*:#: {
  if (%flood [ $+ [ $nick ] $+ [ $right($1,-1) ] ] > 0) { notice $nick You must wait $duration($v1) in order to insult someone again. | halt }
  set -z %flood [ $+ [ $nick ] $+ [ $right($1,-1) ] ] 10
  var %x $mid($1,8)
  if ($3-) { msg # Your to stupid to even insult anybody. | return }
  if (%x == 1) msg # $2 If I wanted to kill myself I'd climb your ego and jump to your IQ. 
  elseif (%x == 2) msg # $2 It looks like your face caught on fire and someone tried to put it out with a hammer.
  elseif (%x == 3) msg # $2 It's kinda sad watching you attempt to fit your entire vocabulary into a sentence.
  elseif (%x == 4) msg # $2 You must have been born on a highway because that's where most accidents happen.    
  elseif (%x == 5) msg # $2 I'd like to see things from your point of view but I can't seem to get my head that far up my ĀŠŠ.. 
  elseif (%x == 6) msg # $2 Is your a$$ jealous of the amount of shoot that just came out of your mouth?    
  elseif (%x == 7) msg # $2 I don't exactly hate you, but if you were on fire and I had water, I'd pour the water out.      
  elseif (%x == 8) msg # $2 Your family tree must be a cactus because everybody on it is a prick.   
  elseif (%x == 9) msg # $2 I just found out your birth certificate is an apology letter from the condom factory.   
  elseif (%x == 10) msg # So, a thought crossed your mind? Must have been a long and lonely journey for you $2
  else msg # Invalid Insult 
}

But I think your beter off using textfile.