Hi Anurag,
I believe the gateway you are talking about is
- NOT the gateway in every AS ABAP
- NOT the gateway in AS Java (SCS instance)
- The Gateway in below link:
SAP NetWeaver Gateway - SAP Library
If so, this is more of a NetWeaver Gateway issue, than an EP one.
I don't know if NetWeaver Gateway has implemented such an option - most likely it has not.
User Management - SAP NetWeaver Gateway - SAP Library
As mentioned in above link, I think Identity Management should be a more feasible solution.
BR, Tom