SAP Portal in a reverse proxy scenario

All,

we have a SAP NW Portal 7.3 running some applications (mostly java WebDynpro) available on Internet.

At the moment, the client connects to a dispatcher that redirects to the Portal butthis one replies directly to the client with its internal server name.

Now, to hide the Portal server name+port, I would like to implement a scenario that rewrites URL in both directions like this:

client (portal1.mycompany.com) --> reverse proxy+dispatcher  --> server1.internal.mycompany.com:50000  --> Portal (AS)

Portal (AS) (server1.internal.mycompany.com:50000/xxx/yyy) --> reverse proxy --> (portal1.mycompany.com/xxx/yyy) --> client

I am testing a solution with SAP Web Dispatcher and I am able to dispatch (rewriting) the incoming URL to the Portal

BUT I do not know how to send back the URL from Portal to client via reverse Proxy, rewriting the URL accordingly.

Is there anyone who has implemented successfully such a scenario ?

Any help would be appreciated.

Thank you !