Hello JSW W.,
I guess you are asking about docking panel not NUIPanel.
if so, you can add a button to the right side of the panels' header using NCaptionButton:
NCaptionButton button = new NCaptionButton(buttonID);
nDockingPanel1.Caption.Buttons.Add(button);
There are predefined buttonID's defined in CaptionButtonID enum. However, you can set any int value for button's ID.
To handle button's click event you need to attach to panels's CaptionButtonCliecked event.
Best Regards,
Nevron Support Team