Docs for outputting XML suitable for OG use

I'm looking at a way to get map view data from Eastgate's Tinderbox (TB)
into OG for visual polish of 'finished' TB analysis. TB can export XML so I
figure I ought to be able to make some OG importable data. However, it seems
the OG Graffle files, whilst XML aren't documented.

I'm wondering whether it might be easier to go via VXD (though I don't have
Visio) given that Windows apps tend to have better/more thorough
documentation - I've seen some for VXD on MSDN.

Note that I'm after porting TB *map view* data and not outline data. If it
was the latter I'd have other options in terms of OPML or OmniOutliner, etc.

Am I proposing a pointless quest.  Although I've some scripting expertise
I'd not class myself as a programmer (in case that's pertinent).

Regards

Mark Anderson