Reusing a JPanel in NetBeans GUI Designer

This is in NetBeans 6.5, Java 6.

I have the following hierarchy in the NetBeans GUI Designer:

JFrame
  JTabbedPane
    JPanel X
      <...>
    JPanel
      JButton
      JPanel Y
        <...>
      JButton

Question:

JPanel Y is identical to JPanel X, so I'd like to simply reuse JPanel X in both places, but how do I do this inside the GUI Builder?

Attempts:

I tried copy-pasting JPanel X, but it creates a full "deep" copy (JPanel X1, etc), duplicating everything in JPanel X.

Some googling indicated it might be possible to add it to the Palette, but I haven't found a way to add a simple JPanel to the palette (as opposed to a complete JFrame).