This is an interesting topic.
By guessing your domain registrar
doesn't give you a
DDNS service, what you can actually do is create a
CNAME record for
www (or any other subdomain) to point to
example.dyndns.com (in case your are using DynDNS as your DDNS provider).
What you can't do is point an
A record to
example.dyndns.com, because an
A record needs to be pointed to an
IP, not a domain. Using only a
CNAME, the problem is your website
will not be reacheable by using example.com (which needs an A record), so your website will only work using a subdomain, like
www.example.com, or
private.example.com. I you don't understand what I'm saying, just ask.
If I'm wrong on something, or anybody has a better idea of how get this done, just leave a comment here. Thanks.....