/help example script

Seriously though, the mIRC help file is an *excellent* source of documents on scripting. I myself learned scripting solely from this file, with no examples save the ones provided in there.
Many of mirc's functions are intuitively named - for example, /window opens up a window

If you want to do something, and do not know how, a quick search through the mirc help file will usually tell you all you need to know.