So I solved this myself.
This page will give you either HTML, XFBML, iFrame or a URL => https://developers.facebook.com/docs/pl ... ike-button
However, the url option looks a bit crappy, since it opens up a new page with just the button on. So i wouldn't recommend pointing to that.
So instead what you can do is a html build, but choose to add the advert bar. You can then edit the source code to include the html for your like button.
The only problem with this is you have to do it every single time you do a new build. Is there a feature in C2 that allows you to specify this so its included in the build?