iframe integration of a local webserver

[firemike]

In zimbrawiki there is a description, how to create a tab-application loading an iframe as the tab content.
ZCS 6.0:Zimlet Developers Guide:Examples:Tab iFrame - Zimbra :: Wiki

That works fine, integrating a website like phpBB-Forum from internet.

.. name=\"tabiframe-app\" src=\"http://www.exampleforum.com\" ..

Question:
If i move these phpBB-forum onto a local webserver without connection to the internet but reachable by my zimbraserver:
How can i integrate this "local" content into an iframe-zimlet now?

The result would be a worldwide reachable, secured forum inside a zimbra-account...

[hmmblah]

You would need to use your zimbra server to proxy the page to forward it on to zimbra users.

I've tried to do this myself to forward some internal servers to a zimbra account, but I only get "Access Denied" on the Zimbra side when requesting the pages. I've posted here to ask how to fix this but got nowhere.

Edit: Here's my thread...from June.

First time Zimlet creation...Proxy