jartse,
It depends how your network is setup to determine how to reach your website from an outside source. If you have a router, it probably allows port forwarding if not, you can use the ip address given to the specific computer. Now you must determine if the ip address is static or dynamic(changing constantly). If your ip address is dynamic like most dsl and cable providers do, I would recommend using an dynamic ip address sniffer such as tzo.com or no-ip.com can provide for a free trial basis. Download the software and install it on your computer. It then allows you to create a domain name for your ip address. The program can monitor your ip address every 30 seconds and change the ip address with tzo or no-ip to match you domain name. It has been a while since I have had such problems, but If you have more problems, just let me know.
-drew10