Multiple Items, Multiple additional item fees

I have a client that has over 400 items in the shopping cart. I am trying to figure out if Zen-Cart can do what the client is wanting. Example:

Item A U.S.: Shipping $12.00 additional items $2.00
Item A Canada: Shipping $15.00 additional items $3.00
Item A Worldwide (Everywhere else): Shipping $20.00 additional items $4.00

Item B U.S.: Shipping $2.00 additional items $0.50
Item B Canada: Shipping $3.00 additional items $1.00
Item B Worldwide (Everywhere else): Shipping $3.00 additional items $1.00

Item C U.S.: Shipping $6.00 additional items $2.00
Item C Canada: Shipping $8.00 additional items $2.00
Item C Worldwide (Everywhere else): Shipping $12.00 additional items $2.00

Granted, this is just for 3 items. Imagine 400 more. After a couple of hours of browsing through the forums I think I saw that this could not be done. I apologize if I missed a thread that gave a more clear picture.

Thanks for your help in advance!