C# How to copy nodes between two identical xsd generated classes

Whats the fastest or perhaps optimal way to read elements, node, attributes from a source class, which represents a chunk of xml, and write then back into a resultant class from the same schema.

I've got a requirement for a way to read incoming xml messages, parse them with this xpath path expression language we have invented, and then write into to a resultant 开发者_开发知识库composite xsd generated class. Both classes are the schema. The schema allows 1.n for certain nodes, but in general the schema is very well designed and is fairly flat.

You'll have to do this via XML, before the XML is deserialized into the objects.