create credit memo request with reference to a sales order using bapi

[aditya_abap]

I need to create a credit memo request with reference to a sales order through abap code , analogous to the copy control available for creating credit memo requests in va01 . I tried using bapi BAPI_SALESORDER_CREATEFROMDAT2,BAPI_SALESDOCU_CREATEFROMDATA1, BAPI_SALESDOCU_CREATEFROMDATA. But i am getting error Permitted combination of business object and SD doc category.

I am able to create a credit memo request using FM : sd_salesdocument_create but i am not able to create it with reference to a sales order . Even after populating fields of ref_doc and REFDOC_CAT ,the credit memo just appears in the flow of the reference sales order but it is not getting created with the details of sales document no. entered as reference.

Please help.