HTTP.CONF - Limit access to url based on application??

scenario: I have apache, 2 x j2eee containers and a proxy
running on the same host.

One of the j2ee containers will acccess webapplications in
the other j2ee container through apache. However the one j2ee
container thats getting requests from the other j2ee container
must not be directly accessable from the internet.

Since I have a proxy on the same host as apache, I cant limit
access to the j2ee container based on hostname ("localhost")
because the proxy makes connections from the internet look like
they origin from the localhost, just as request from the other
j2ee container - thus I cant limit access using <directory> or
<location> in http.conf based on hostname. Is there som other
way to make apache limit access to only allow the j2ee
container based on applicationname or something else?