Is it possible to have a sale price based on a rate card

e.g. A user enters a sale for a delivery to somewhere in the UK. I plan on creating a module to hold charges for our customers that are then ttached to their account. When a user enters a sale and enters the delivery address, can it somehow reference an attached rate card and show the price on the sale?

I am guessing it is possible but a big job. Anyone know where to start with this?

Version 6.2