How to modify Preferences tab and add new tab on the web UI?

I want to and new tab in the Preferences tab .like click Preferences tab and show "New feature".
How can I do those?
Thanks

See https://bugzilla.zimbra.com/show_bug.cgi?id=60684.

vmahajan , Thank you very much for give me a hint to modify standard Client web UI.and I have modified "HTML" web UI on the preferences .
Now, I wish add same tabs in the advanced client web UI.
I have found topics ,but I can not find how to do it.
How could I do ?
thank you very much!

For advanced client I think you would need to write your own zimlet.

vmahajan, thank you very much.
Yes, as you said. I have added new zimlet. I want to add new feature in this zimlet.
and I want to modify "preferences" tab too.
How can I do it?
thanks very much.