There doesn't seem to be any way for a script using the ON CHAT event to differentiate between normal messages and ACTION messages.

The specific problem I'm having is with a script that was written for mIRC 6.16. It requires '/me attacks' commands in DCC CHAT. This is the event that is used:
Code:
ON 2:Chat:ACTION attacks*:{

However, I'm running the script on version 7.29. And it doesn't work. I did some investigation, and I found that this was being returned in $1- in the CHAT event:
Code:
attacks Zombie

Whereas in version 6.16 I got this:
Code:
ACTION attacks Zombie

Which means the script isn't forwards compatible, and there's no reliable way to differentiate between normal messages and actions in DCC sessions.

As long as we stand, we will fight!