Floating frame with multiple parents??

Hi guys,

here is a problem that seems simple, but I could solve although I
tried hard. Maybe anpyone has a helping idea.

In my application, there are document and tool frames. The tool
frames should float above all document frames. The problem is, that
usually a frame can only float above its parent, i.e. above _one_
single window:

style=wx.FRAME_FLOAT_ON_PARENT | wx.FRAME_TOOL_WINDOW

What can I do to make it stay above _all_ document frames?

Thanks
Christof