Hi - can anyone help please?

I have created a Theme which I have deployed to the relevant areas on my machine and I wish to make this Theme the default when opening PowerPoint (and obviously the other applications but I'll worry about that after this has been resolved) !!

When opening PowerPoint the default Theme appears to be "Office Theme". After checking through the Themes available under "C:\Program Files\Microsoft Office\Document Themes 12" this does not appear in the list. I have checked the registry in case it is floating around in there but alas no joy.

Does anyone know how I can access this Theme?

I have looked at Word and am aware that the "Office Theme" is within Normal.dotm (changed the extension to zip, opened up the zip and found "theme1.xml"). Is there an equivalent in PowerPoint?