CRM Add Postnet address to BP

Experts

We are on CRM 4.0 and the business never use to maintain Postnet Addresses but only Standard address in which they capture Postnet addresses as well. We now moved away from this and for some BP's I need to add the Postnet Addresses without having to remove the old Postnet under the standard addresses. Manually it will go under the ADDRESS OVERVIEW tab and add and then list under the POSTNET address link. This would technically go into table BUT021 for addresstype LIEFER.

I cannot get this done with the BAPI_BUPA_ADDRESS_CHANGE. This gives me no return error but also does not update the BP at all. What I do is I populate the ADDRESSDATA and ADDRESSDATA_X tables with the new address I want added. I also populate the ADDRESSUSAGE table with LIEFER and X and the ADDRESSUSAGE_X with the relevant 'X'. Nothing else seems to be relevant.

Thanks in advance

Anina