Thank you for sending the additional details.
The required approach cannot be achieved with the built-in functionality of the control. However, I would suggest that you remove the AutoHideArea and add an additional control ( for example RadListBox) which contains the panes as tabs. With the help of some events of both ListBox and Docking controls, you will be able to show the unpinned panes and to change the highlighted tab according to the Active Pane. I have attached a sample project to demonstrate the approach, please note that this is just an example and we cannot guarantee that it does not have side effects.
I have used Implicit Styles to apply the theme in the project, more information about this can be found here
the Telerik team