How to add costs to the product COGS after shipping it

Summary

We get to know some costs like transportation after shipping the product. There is no WIP Work Order involved.

Content

We receive items in our inventory by either inter-organization material transfers or miscellaneous receipts. We sell and ship them to our customers using the OTC cycle.  However, there are some costs that we get information on, after we have shipped the product.

How can we incorporate those costs to the product COGS and eventually to the gross margin report?

We cannot use LCM functionality because the primary item is not received against an external vendor's PO. 

There is no WIP work order involved.