I believe this has been implemented in resources/include/std_zh/astar.zh:

HTML Code:
// Credits to Lejes for making the A* algorithm actually work in ZC! I probably wouldn't have ended up making my version (which is older than this) work without the assistance!
// Optimised for 2.55 on 24th May, 220 by ZoriaRPG.
I'm impressed that Zoria implemented this all the way back in 220 AD. Tell me, can I borrow your time machine?