Reverse Proxy

I am experimenting with allowing public access to an HTTP server
that's on a publicly
inaccessible box.  It seems simple enough, but I can't seem to get it
to work properly.  It looks as if the server is just rewriting the URL
to the internal address, rather sending the request to the back end
server, getting the response and sending it on through.

Here's what the admin GUI added to my config file:
ProxyPass /login.jsp http://199.5.86.71/login.jsp
ProxyPassReverse /login.jsp http://199.5.86.71/login.jsp

When I attempt to access http://www.simplyexpresslink.com/login.jsp,
the URL gets rewritten in the address bar to
http://199.5.86.71/login.jsp

I'm sure I'm missing something, but everything I see on the web tells
me that this should work.

Thanks!
Mike E.