Update staging area LIPS-LGBZO for a delivery

Hi,

I am looking for a bapi to update staging area for delivery items. The requirement is to update LIPS-LGBZO through a custom program.

I have tried using WS_DELIVERY_UPDATE_2 and  SD_DELIVERY_UPDATE_PICKING, but could not get it to work. Please suggest.

Thanks in advance!

Regards,

Sri.