[camlorn]

Since no one else has chimed in:

Firstly, it's probably better to ask on any official client forum. If cmud has a forum try there.

Secondly, this involves a few things and probably isn't worth it.

You'll have to turn a trigger on when the flee message is received. Essentially, you're going to need two triggers, one that catches the flee message and another, normally disabled, that catches the leaves north line.

The bad news is, given the leaves north line only has one constant word, you have to use this approach or multiline triggers which only mushclient has any support for at all (and even then, I haven't found a document for that checkbox and don't know how to use it). In order to do this, you're looking at intermediate scripting, at least, possibly more depending on what to do with it.

You're the first person, ever, I've seen asking for help on cmud, so I'd not expect a fast answer here (this is when someone chimes in and proves me wrong). Find the client's official forum.