I have something like this
myhost.dyndns.org. When I put
myhost.dyndns.org in browser then redirect me to ADSL modem IP (10.0.0.138) but I try to redirect me on localhost (Apache server). How to solve this
You must set a port forward on your router/modem at least for port 80 to the (local) IP for your server.
Beware, this can be dangerous as anyone can access this website in your private network.