Shopify Affiliate Script - repost

My company is looking to use affiliate marketing to promote its new clothing website. The website runs Shopify. We need a script that allows us to place tracking pixels from an affiliate network onto the order complete page of the Shopify site. From what I can see we need to use the Shopify API to do this. The API documentation can be found here: [login to view URL] You should have a good understanding of Shopify, Affiliate Marketing and speak fluent English. More details on request.