There are a number of options available in mIRC Options for things like that, and if what you're looking for specifically can't be done via mIRC Options, then it can probably be scripted.
Take a look through the different options available in mIRC Options (Alt + O) and see if what you're wanting is already there. If not, post a query in the Scripts & Pop-ups forum with your request, and include a link to this topic as a reference.
