Add flash effect at the end of your animation.
Render last 60 frames to a sequence. Import it. And in interpret properties (right click on imported footage -> Interpret Footage) set Loop parameter to 100 (or any).
Add that new footage to the end of your animation.
I need to explain myself. There is no flash animation I was just explaining (or trying to) how I would do a frame loop in flash. Is there no way to loop frames x to y in AE?