how to enhance the gateway to add additional fields to the OData service

Hi Gurus,

I am currently following this blog.I want to add two fields to standard OData service itself - is there some extension/enhancement points or some other functionality to get this work done.??.

how to enhance the gateway to add additional fields to the OData service for this particular app.

Also there is a similar thread but no reponse.Add a custom field in standard Odata Service Entity

Thanking in advance.

Thanks

Pavan G