I may be wrong about @event. Look in the Interpreter (part 1), and look for an instance variable in the intialize or setup method that defines either "@event" or "@event_id". I can't remember off the top of my head which one it is. If it is "@event_id", use this script call to reference the event:
$game_map.events[@event_id]
or if is "@event", try:
$game_map.events[@event.id]
I can't see why that wouldn't work, unless it is something to do with BABS that I'm unaware of.