Compare and update XML files

I have two XML files that are residing on two different servers (ServerA and ServerB) in the same domain.  There is a section of the XML file that needs to be copied from one server to the other in order to maintain an application setting. 

<Item>
  <Instance>
     <Config>
        data1 data2 data3 data4 data5
     </Config>
  </Instance>
</Item>

I need to leave intact data1 data2 as these contain specific entries for the server the file resides on (IP and such), and are of fixed length.  Data3 data4 and data5 are variable length and need to be copied from ServerA to ServerB.

Any help or hints to the right direction to take would be appreciated.