Unable to overwrite 'Dispatching Country' field in Purchase Order

Hi All,

We are using SRM Extended Classic Scenario with ECC 6.0 as backend.

I am able to replicate some customer fields to the backend system.

However, i am not able to replicate the value under

Item -> Import -> Origin /Destination / Countries -> dispatching country.

Here i need to overwrite 'Default' value with customized value.

Thanks in Advance.