Apache Gateway. How to configure? Is gateway the solution?

Hello everybody! well, my problem is quite simple, but I have no idea how to solve it.

Scenario

At home I have 2 computers, linked by a very simple network. My network is made just by adding a second ethernet card to the DESKTOP computer, and there's a cable coming from the DESKTOP to the NOTEBOOK. Also, in the first ethernet card of the DESKTOP I have a cable modem connected for internet access. The internet is already distributed for the 2 computers.
In both computers I have Apache web server installed, running with PHP.

My Problem

Well, the problem is that the desktop computer is used by my family, for internet and office stuff. And I use my notebook to develop web applications and etc. Everytime I need to show the progress of my work to my clients, or partners, I need to disconnect the NOTEBOOK from my network and directly connect to the cable modem in order to have a real IP ADDRESS so I can give my clients it , so they can access my personal web server on my machine.

THE QUESTION

The question is: How can I give access to the NOTEBOOK while it is inside a network and does not have a REAL IP? Can I setup a gateway in the DESKTOP, so the requests made to the DESKTOP IP will be served by the NOTEBOOK web server? How can I configure that? If that is not the way, how can I do to acomplish this??

Notes: I already tried redirecting from one apache server to the other, using apache directives, but it is not possible, since the IP to the NOTEBOOK is not a internet IP.


Thanks a lot.