SuSE9.3 Inertnet access without seeing internal Network,How?

[Alf1]

Here is the Setup:
Server has 2 Network cards
One For internal Zone
One for External Zone
Internal Zone accesses Internet through a Switch/Hub>Server

Here is what I need to get done:
I need to use my Work Laptop through the internal Network>Internet>back into the Work Network.

I don't want the Work Laptop to have access/see any other PC within the internal Network.

Is there a way of setting it up so that the Work laptop get's access to the Internet through the Server without seing the Internal Network?
I am thinking of a Demilitaryrised Zone but don't want to have to install a 3rd Network card.
The Internal Network has static IP's
The Work Laptop will be using DHCP, so I would have to use it's Mac address to give it access through the Server.
Any ideas?

[leonpmu]

Use the built in firewall, and block access to samba.

[Alf1]

This Forum just lost all the work that I typed in for the last 1/2 hour as it had me logged out :-(