Lawson API maintenance (M3)

In the M3 screen for CRS620 you can enter ????????? and the system will automatically generate a new supplier number (SUNO)

In using the AddSupplier API call (CRS620MI) while the data goes in fine.....passing ????????? does NOT generate a supplier number, and simply stores the ????????? as the SUNO.

How do you modify the API to generate the supplier number ? (or whatever number depending on files you are working with)