Changing URL path or prefix for Java Systems for Reverse Proxying

Question

I am running an Apache Reverse Proxy for multiple systems including Enterprise Portal and GRC.  Unfortunately, the two systems share the same directory structure (e.g. /webdynpro, /images, /logon, /useradmin, /VC).  The reverse proxy won't be able to differentiate URLs for the two systems.
I want to add a prefix (e.g. /grc/webdynpro) or change the URL directories (e.g. /grcwebdynpro) for Portal or GRC.  How can I do this?

Answer 1

Thank you for the reply, but could you explain?  It seems like this wiki is suggesting how to change the default port and start URL and how to configure reverse proxies in general.  It doesn't seem to answer the specific question that I have.
I need to add or modify the URL so that it is unique to the reverse proxy.  For example, EP and GRC both use /webdynpro.  I would like one of them to use a completely different structure (e.g. /grc/webdynpro) so that the reverse proxy can differentiate requests to different hosts.
The reason why changing the Start URL doesn't seem like the answer is because the fundamental directory structure is still the same.  The reverse proxy won't be able to differentiate the different requests because of this.
I am looking for some kind of configuration that lets me add a prefix to the entire web application server.  Is anyone aware of this configuration or know of an alternative solution?