|The easy way is static on the public side of your connection.|
That way either you can point with a Fully Qualified Doman Name or simply an IP address (port optional).
Most people have home isp's that offer dynamic and the IP address's change rarely to often depending on things. A common solution is to use a dynamic dns service, your router may support it or you have to use a small program to tell the service you new ip address. Most are free for some rules.
ISP's also offer static ip's for a bit more.
Playing to the angels
Les Paul (1915-2009)