Webmin / Usermin and port blocking

[Bob Brennan]

> You can bind both services to different ports of choice.
> 
> $ grep 10010 /etc/webmin/*
> /etc/webmin/miniserv.conf:port=10010
> 
> You can do this by hand editing the configuration file or inside the web
> browser surface of the tool.
> 
> Alexander

Sorry - let me re-state the problem. I want to access from a computer
that is blocked from directly accessing any ports other than http:80.
I can't even use a POP or SMTP connection to the outside world because
ports 25 and 110 requests are blocked, so
http://myserver.net:anynumber will not work. It would have to be as
http://myserver.net/usermin.

The question is how can I (or "can I") route a request to an http:
directory or file to the Usermin interface on localhost:20000? Or
access the Usermin pages as normal html/php/whatever directories/files
instead of a port interface.

Thanks in advance,
bob