AR Customer Interface for loading customers from a third party system

We are currently looking at creating a new customer interface to our Oracle AR module on platform 12.1.3. We are having a problem entering AR customer records using the standard customer interface program.

When importing customer records from a third party system into Oracle AR if you do not populate the ORIG_SYSTEM_PARTY_REF column with an original system reference number for a party, the system assigns the imported customer reference number from the ORIG_SYSTEM_CUSTOMER _REF column to the party as well as to the customer account. During the import process Is there a way of loading customers if you provide the existing party's original system reference number when you create a new customer account for an existing party.