Country Name issue in syncing Sales Order

In  Sales CRM-BC integration, for the tables like Customer, Vendor and Contacts, I have resolved the Country/Region code issue by using a custom Transformation Rule but for the Sales Order, there is no Integration table mapping from Sales CRM and so there is no way I can transform the Country Name to country code.  Due to the country name, the Sales orders cannot be synced from CRM to BC.  How to resolve this issue?

Thanks and Regards.