Any DynamicDNS providers that support RINETD?

Hello,

I was wondering if anyone knows of any DynamicDNS providers (like
dyndns.org) that also provides support for "rinetd" (port redirector)? My
ISP blocks incoming requests on port 80. As I understand it, most (if not
all) dynamic dns providers currently use "URL redirection" - i.e., modify
the URL to add the non-standard port to the end. The client browser then
connects to the web server on that particular port. I have a couple of
concerns with this approach: 1) It doesn't look so nice having the
non-standard port stuck on the end of the URL, and 2) Some corporate
firewalls do not allow outbound traffic on ports other than 80 and 443 -
thus, clients behind such a firewall would not be able to connect to my web
site.

If I understand it correctly, with "rinetd" the browser would connect to
port 80 on the dynamic dns service provider's hardware; rinetd would
transparently "proxy" the requests to my web server running on a
non-standard port.

Is my understanding above correct, and if so, any dynamic dns providers that
support rinetd (or equivalent sort of port forwarding)?

Thanks,

Mike