Process only unique xml files found, which don't match ConfigurationID

Hi All,

I do a search for xml files in a dir which contain the following inside each of them, and place them into a variable $xmlpath:

<?xml version="1.0" encoding="utf-8"?>
<Configuration
xmlns_xsd="http://www.w3.org/2001/XMLSchema"
xmlns_xsi="http://www.w3.org/2001/XMLSchema-instance" id="root" version="1.0.0.1" configurationId="64bbabac-1fc5-4a5e-823e-d3a76d678210">

Now I want to only process each of the files found, but only if their ConfigurationID is unique compared to the other files in  the list of files found.

How best to do it?

Thank you,
Mark