I know of no such method.
What is it you're trying to create?
Still, PPro's ExtendScript API allows for full control over the XMP associated with any given media.
So, again; what is it you're trying to create?
i need to pass cars object to c++ shared library, but TaggedData structure does'nt support this, so i was wondering if there is some other way i can pass this cars object
Let's leave aside the implementation details for a moment...
Could you provide an overview of the workflow(s) you'd like to support, from the user's perspective? That will help me give better guidance. [write me at b b b at adobe dot com, if you'd rather not discuss those workflows in public.]