HTTP Customized Status Code in MII

Hello Experts,

MII receiving the message from message brorker(IIB) system and in MII  doing the Schema Validation  if any problem with message structure or missing filed in the message we want to send the  customized HTTP Status Code :500 back to the source system.How to set the  customized  HTTP status code in MII  if any error occured?

Note :Currently success status code 200 going to the source system even for invalid message.

Regards,

Shanmugam K