Ajeh:
COD is a Payment module ...
The COD FEE is an Order Totals Module that bases the Extra Fee on the Shipping Module that is selected ...
If the Shipping Module is defined in the:
/includes/modules/order_total/ot_cod_fee.php
Then a Fee can be added ...
If your Shipping Module is not in the Order Totals Module COD Fee ... you would need to add it or customize the module as described above ...
Then, uninstall and reinstall the COD Fee Order Total Module to see the changes that you have added ...
WARNING: if you already have the COD Fee Order Totals Module installed and customized, you need to edit it first, and record your custom settings as they will be reset to the defaults when you uninstall and reinstall it ...
The Situation is this:
a) a customer can order a shipping by post but pay immediately the product with a credit card or with a bank payment module (money instantly from the account transferred).
b) a customer can order a shipping by post but pay inly when receiving the package in the post office. Post office takes extra fee from the shop keeper from that service.
So, in both cases the customer uses shipping BY POST but in the case b) he needs to be charged of COD fee as well. So, he would need to know by the law what is the total price when confirming his order. Thus, I would need to add it somehow for the price ONLY in the case he pays via COD using Post Office, not when paying otherway and using post as well.