How to load the customers in MDG (not created as BP in ECC - reuse mode)

Hi

I have a unique situation and need suggestion.

We are creating BP from MDG which is implemented on top of ecc (not a hub) BP's are created for specific account group from MDG and transferred to CRM (through PI - SOA activated) - working fine.

Prior to MDG implementation, for a specific account group, the customers were created as normal customers and not as BP in ECC, hence can't view it or change it from MDG.

The requirement is to create the data in MDG for those specific account groups and move it to CRM. I can create one by one records in MDG and data is transferred to CRM without any issue but there are many such records which we want to move it to MDG from ECC. Don't want to create it manually one by one.

Any idea whether this is feasible? If yes how? Can we use Import option and create customers for those specific account groups?

Appreciate your help.

Thanks

Kiran