Global Shipping Program Shipping multi purchases

[crabbingbayman]

One international buyer won 3 auctioned items.  As I have no control over the invoice to be sent, how do I combine the 3 items into one box for shipping to save a few dollars for him.  I automatically do this, when possible, for any buyer - this is my first time with an international buyer.  He is inquiring as well with me.  Hopefully someone has an answer for me.  Thank you.