Transfer of MDG records to CRM

Hello All

Need guidance on following queries.

In our system, customers are replicated to CRM through PI. The integration is working fine. Now the requirement is to transfer some of the records from MDG to CRM. Need advice how to achieve this?

1. Get all the ship to accounts with an indicator into CRM via MDG - Don't want to update each record

2. All the inter company records to be transferred from MDG to CRM.

Can we do this using file upload and download or any other better way of doing this?

Please suggest the best practice and way out.

Thanks

Kiran