How to find docked pane location?

In my application I am adding panes dynamically but if there is already a pane docked at the bottom of the frame then I would like to add the new pane as a tab to this one, otherwise just dock the pane to the bottom as normal.

My problem is that although I can enumerate the pane list and find all panes that are docked, I can't identify which side they are docked to.  I know I can get the WindowRect from the pane and probably work it out from this but surely there's an easier way?

add public memeber (in next version we will add it too)

XTPDockingPaneDirection CXTPDockingPaneManager::GetPaneDirection(CXTPDockingPaneBase * pPane)
{
 ASSERT(m_pLayout);
 return m_pLayout->_GetPaneDirection(pPane);
}