Stab riser in Logic?

Hi

Really liked the stab riser technique (in Advanced Techniques - Drums, Breaks & Builds) of shortening the loop length over time with automation. Thought, hey id try that in Logic, but alas the EXS24 doesnt have the ability to automate the loop length. Thought long and hard about how else it could be achieved but cant come up with anything. Does anyone know a way of repeating this technique in logic? I did ‘start’ to continually shorten the midi notes in the track so it would play a shortened sample each time but this was not only massively time consuming it didnt give results anywhere near as good. Any suggestions gratefully received.

Cheers

Greg