[SOLVED] Need to add a affiliate conversion pixel to a specific page

For a site I have built, I need to add an affiliate program conversion pixel to a 'thank you' page, which is actually a normal page, added through the dashboard.

Since all pages use the index.php of Atahualpa as a template, I would need to add code in there that calls the thank you page by id and then echoes the conversion pixel in that page
The one thing I am not sure of is what code to use to make that pixel echo only on that thank you page.

The pixel code is:
Your help is greatly appreciated!