Forum:Help with a Wikia Extension

Hi! On my wiki, I'm planning to insert some sort of javascript code called a Countdown. My problem (not one you would expect) is that my wiki doesn't even have a viable "script file" to put it on. This script file (one that wikia almost always has) is called MediaWiki:Commons.js. I don't think that anyone has ever created one on my wiki. Could someone please either do it for me (if you're capable) or give me a detailed guide on how I may ask for or create one myself? Please, let me know if you can do it yourself and I will give you a link. Thank you! Salience72 (talk) 13:52, September 3, 2012 (UTC)
 * You search for it, and the page should appear nonetheless.--PedroM (talk) 16:20, September 3, 2012 (UTC)