WordPress and Facebook Tabs

I have created a custom wordpress theme to create a Facebook application/page tab. All is fine. However, I would like to create a Fangate for this application. The fangate that I’ve used in the past works great with non-Wordpress applications (https://github.com/Maggo/fb-fangate).

Here is my issue, the fan gate’s index page must be the first file that is opened (index.php). However, as we all know, WordPress runs off of ‘index.php’. I used .htaccess and the code ‘DirectoryIndex fangate.php’ to have the fangate run and not have to touch wordpress’ ‘index.php’ file. Everything works fine, except now I am unable to go to my WordPress dashboard. It just looks like a linux list of files (it looks like this: https://bit.ly/LEiA9k). Does anyone have any good recommendations on how I should go about this? I tried a WordPress Plugin called Facebook Tab Manager to create a reveal page, but it doesn’t actually do what I need it to do.

Is there maybe a way to change the name of WordPress’ ‘index.php’ file using a function or something?