Hi there, if you are looking for the additional fee function for your calculations, try the Shipping Rules module. It allows you to modify live shipping rates: surcharge, deduct or override rates, provided by carriers.
With the extension you can modify rates both for individual products and for whole orders:
- If there are specific products in the cart, you can increase, decrease or determine shipping rates for the whole order. .
- Also it is possible to apply the actions to individual products - e.g. give 3 euro shipping discount for each camera.
Below you can see the way all the rules you create are displayed as well as how to specify the products to apply the rule to: