One-time customer with ERP Sales Order

Hello experts,

I am working with ERP Sales Order on SAP CRM 7.0 Ehp3.

We have a requirement to start using 'one-time customer' process. I know there is a standard account groupd (CPD) on ECC side for this purporse.

We would like to enter a sales order for occasional customers, without saving the customer in the master data table.

I would like to have an occasional customer (example nº 1000 which should work like a CPD). I need to enter a sales order for this customer nº 1000, and once I enter nº 1000 on the BP number field, it should bring a Pop-up in order to enter the customer's information (address).

This is working when I create the order via VA01 on ECC side, but the pop-up is not shown when I try to create the order on CRM via erp sales order.

Any suggestions on how to make one-time customer work on ERP sales order? And how to make the pop-up work?

Thanks in advance!

Luis