BAPI Enhancement for updating database.

HI,

My task is to enhance a BAPI structure in SRM, "BAPIBUS1006_CENTRAL_ORGAN",

where, when I am trying to append structures its telling me that the BAPI structure cant be enhanced. PLease find an alternative route, or else tell me how do I add some fields which are already in the SAP tables, to the BAPI.

Regards,

Gautam