I can't speak for a resource for you to look at, but your snippet is incorrect; the matchtext is a regex (regular expression), and so the $ event prefix must be used.

Code:
on $*:TEXT:/!banlist (add|remove)/Si:#:


Regular expressions are a defined syntax for matching text and is not directly related to mIRC, for more information on that you can see here: http://www.regular-expressions.info/, the mIRC specific part here are the modifiers at the end, // is used to surround the regex and the modifiers are specified afterward. 'S' strips the incoming text of all control codes (bold, color...) and the 'i' is for case insensitivity.

Access levels are used in triggering events, you use them in place of the *, I suppose you could use $level to do so within an alias but it probably isn't the best way to structure it.