Create dynamic page content from custom Wordpress plugin page

I would like to create a custom Wordpress page from a plugin displaying content that is not from Wordpress with 2 get parameters and apply rewriting rules on it.

Let's say I have a file called test.php. I would like with 2 get parameters to display content using the URL:

http://ift.tt/1XjkOQU

I'm good on the plugin side (Admin, etc...) but have no clue about custom page. At the moment I have this code in my test.php file but I'm really not sure if that's the right way to do:

include('../../../wp-load.php');
include('myplugin.php');

global $myclass, $wpdb;

echo $myclass->get_setting('test');

Or would I need to check query vars parameters passed in URL and modify content accordingly?

I tried some stackoverflow answers without success so if you could hint me up on this. Thanks a lot in advance.

via Chebli Mohamed