Req. to know, to which to pass prmontl discnt in BAPI_SALESORDER_SIMULTE

Hi SAP Gurus,

I want to get the trade promotional discount when order is simulating. Hence i am using the bapi BAPI_SALESORDER_SIMULATE , and i don't know to which field i have to pass promotional codes in this BAPI .

Please let me know to which field i have to pass the promotional codes to ge the promotional discounts.

Thanks in advance.

Regards

Harikrishna