cmd_ei_api=>maintain_bapi to update partner functions

Hi,

I am using  cmd_ei_api=>maintain_bapi to update a customers partner functions. In my example I have a customer with the partner function WE (ship-to) already existing. I want to add now another WE partner (dummy number) to the same customer.

When I use :

object_task = 'U'

sales_tast = 'U'

functions-task = 'I'

it tells me that the same role already exists and I cannot create it. So my customer should have 2 ship-to parties, one is the customer number itself and the other is a dummy ship-to party, which is always the same for all customers.

When I use functios-task = 'M' then it overwrites the existing ship-to party with the dummy number.

Any ideas?

Thanks,

Tim