I have never used bersIRC so I may not be fully understanding what you mean, however, mIRC does have a Script Editor. You can load scripts via File > Load or via the /load command. You can unload scripts via File > Unload or, *Shock* via the /unload command. You can access the script editor by pressing ALT+R
There are several mIRC-scripting-related websites that have a huge archives full of scripts, including www.mircscripts.org
. More links can be found here
Is this what you meant?