dynamic address and fqdn behind router
I have a fqdn of kc8tdw.com, however this is one a dynamic i.p address. I have a program that updates freedns.afraid.org. I have the warning of "Warning : Your dns/server ip seems your local/private ip. in order your server be accessible from outside, you should set it to your outside/real ip (your modem/router's ip)", with a dynamic i.p. address, I can't do this.
Also, I would like to type in my web browser kc8tdw.com and get to my site, with out getting the default page in /var/www/.
Can you please help?