If you don’t require that the custom title-bar differ from OS to OS, then you might be able to do it something like so:
- Have the window be generated without decorations
- Depict your own title bar using Panda elements (perhaps via DirectGUI)
- Use mouse-events to detect attempts to drag the window, and then set the window’s position accordingly.
There are likely some pitfalls in doing so, however. For example, I seem to recall that Panda stops sending mouse-events when the mouse exits the window, meaning that too fast a drag might result in the window no longer responding until the mouse re-enters it. I’m also not sure of quite how the Panda window will behave if you attempt to place it in this manner.
Still, it may be worth trying!