Here's a sample of what I've been using.

Code:
on *:text:*subscribed*:#:{
  if ( $nick == twitchnotify ) && ($istok($1-,subscribed to,32)) halt
  elseif ($nick == twitchnotify) && ( $4 == while ) halt
  ; Custom New Sub Message
  elseif ($nick == twitchnotify) && ( $4 == $null ) { msg $chan MESSAGE  }
  ; Custom Message Per User
  elseif ($nick == twitchnotify) && ( $4 isnum ) && ( $1 = nokz ) { msg $chan MESSAGE }
  ; Custom Message For Months Subbed
  elseif ($nick == twitchnotify) && ( $4 > 5 ) && ( $4 < 12 ) { msg $chan MESSAGE } 
  elseif ($nick == twitchnotify) && ( $4 == 12 ) { msg $chan MESSAGE} 
  elseif ($nick == twitchnotify) && ( $4 > 12 ) && ( $4 < 18 ) { msg $chan MESSAGE }
  elseif ($nick == twitchnotify) && ( $4 > 17 ) && ( $4 < 20 ) { msg $chan MESSAGE }
  elseif ($nick == twitchnotify) && ( $4 > 19 ) && ( $4 < 24 ) { msg $chan MESSAGE }
}