Create XML Nodes based on XPath?

Question

Does anyone know of an existing means of creating an XML hierarchy programatically from an XPath expression?

For example if I have an XML fragment such as:

Answer 1

Here is a enhanced RegEx based on Mark Miller's code

/([\w]+)(?:(?:[\[])(@|)([\w]+)(?:([!=<>]+)(?:(?:(?:')([^']+)(?:'))|([^']+))|)(?:[]])|)|([.]+))

Group 1: Node name
Group 2: @ (or Empty, for non attributes)
Group 3: Attribute Key
Group 4: Attribute Value (if string)
Group 5: Attribute Value (if number)
Group 6: .. (dots, one or more)