It still works for me. Both in editbox and in remote script events. mIRC 7.41
On *:CHAT:*: { msg =$nick you said $1- }
This will cause an endless loop if you chat yourself.
In case you weren't aware, by prefixing /msg with a '.', it will silence the command so that it appears that nothing happens.
Your '.msg =$nick' may be working but you're unaware it's working.