Google Ecommerce Trakcing Code for Zen Cart

I need to get ecommerce tracking working with my Zen Cart store. I have put the basic code into my [login to view URL] file and goal tracking is working and ecommerce tracking is saying receiving data but ecommerce tracking section is showing no results for purchases. I think that the problem is that I need to confirgure the _addTrans and _addItem parts of the Google Ecommerce tracking code to dynamically pass shopping cart info to google analytics from Zen Cart. Certainly this is part of the problem and needs some php code to get that info to google. I am looking for someone with experience of Zen Cart and ideally google ecommerce tracking who can write these small bits of code and get my ecommerce tracking working.