I've found the weird solution spontaneously somehow.
I've been poking around with WeiDU in an intuitive manner, copied this text:
IF HotKey(K) THEN RESPONSE #100 Rest() END
Then I did save/export this as .bcs file, manually converted it to .bs file and added it to player scripts as custom script? Had no idea what I'm doing, but this custom script was accessible ingame, so I choose it for my main character and then, by coincidence, I had "turn AI on-off function" on my "K" button, so it turned out that I have to reload this party AI functionality and my "resting script" works.
Sorry for grammar