I am new to this. Here is the situation and wondering if someone can suggest best solution to it.

I have domain "www.mydomain.com" where I have magento website running, we are in development stage so I did URL forwarding "www.mydomain.com" to "www.mydomain.net" and we have under-construction page on "www.mydomain.net'. Because we do not want to show development.

I also have subdomain "beta.mydomain.com" which I pointed to "www.mydomain.com/index.php" which works fine. But how can I show this without changing URL in browser from "beta.mydomain.com" to "www.mydomain.com/index.php" this we want to show our development to management.