[mapguide-internals] RFC60 - Possible to use XPath on MgResource classes within server??

[UV]

Hello,

Is there a way to apply an XPATH to a mapdefinition / layerdefinition 
within the server code?
The whole implementation in the server with resourceheaders, 
resourcecontents, resourcedefinitions is quite complex and
not sufficiently documented.
How can I apply XPath to a mapdefinition/layerdefinitions? (in my case 
to extract the colordefinitions)

Thanks for any pointers.