How to add custom hook to back office

[matavz]

Hello everyone,

I'm making a module that should make it possible to add extra information to the Combinations in the back office panel. I want to do this on the Catalog > Product > Combinations page, on the place where you currently can see the UPC, EAN13 fields and so on.

This is the AdminProducts.php file, but how do I add my own custom hook into this?

I've read this article: http://www.prestashop.com/forums/viewthread/12637/ but that only describes how to create hooks in the frontend, and I thus want one in the backend.

Can someone help me with this?

thanks in advance