Query String in Woocommerce

I’ve finally sorted out my issue of a custom cookie filable form for woocommerce. But I’m stuck on a query string for the add to cart function.

I want to have a query string that adds the product to the cart and adds a string line to the order.

So for instance it would show:

Custom Box
– Banana Nut (2), Chocolate Chip (3), Classic (5)

I know the add to cart query string is:
?add-to-cart=

With the product id following that. I know how to add attributes and I’m guessing it has something to do with that. I tried:
?add-to-cart=1974&attribute_custom-selection=this%20very%20long%20string

But haven’t had any luck. Could anyone steer me into the right direction?
Thanks!

http://wordpress.org/extend/plugins/woocommerce/