GDBalistic you can layer transparent (frameless) widgets.
It's not possble to do a tabbed system with just one widget as they aren't dynamic.
Once setup, they are setup...with the exception of hiding/showing certain elements.
However you can achieve the look you want with layered widgets.
Here's an example:

The menu is actually a transparent widget with an image of the interface layout/button graphics as a single image.
Then a second transparent widget is opened over the top that puts the content/actual clickable buttons above the backdrop image over the top of each button graphic.