Scripts

There isn't one. It can be emulated for a single map if you process the map.xdb.

Added 1 minute ago
What is the goal? Perhaps there is another solution.

I wanted to create a special ability for a hero that would improve the mood of a hostile mob when attacking it, making it more likely to join.
For now, I've just made it so that there's a chance of a friendly mood appearing (without taking into account what the mood was before) - and that works too.