If you wanted to show Carriage In on the accounts, it's easy enough to add.
Go to top menu Set Up >Accounts > All. When the pop up box listing the ledgers with the accounts appears, click on Cost of Sale. The grey bar will turn blue, and the option button New becomes available. Click on that and add your new account Carriage In, click Ok. Close the main box, job done, it will now appear as a Cost of sale account.
If you do not want to add a new account, you could do as you suggested.
