There's a whole section of it on the wiki. Search 'Lua'

By the way, don't post on really old posts, it's called a necro. They're frowned upon, and can get you banned. If it's a really urgent question, which you have to be very sure of, start a new forum thread :)

I'll sound like an idiot for this... But how do you do this on the console? Or is this just code to add into somewhere?

Copy and paste the code into Notepad or similar,save as autorun.lua.