How to canonicalize a subtree of XML?

[SM]

Hi,

I am using Xerces-C++ as my XML parser. Is there any API to get the
canonicalized C14n output of a subtree of an XML file? I need to get the
canonicalized octet stream for an element and all its sub elements.

I dug around a bit but could not find any published API for this in xerces.
Any help or pointers on this will be great.

Thanks,
Mosa.