Hello Mark,
you should be aware that if you want to take advantage of built-in XML
coding VIs, the LV schema (that we cannot edit or replace) will prevent your application
to be fully compatible with XML-RPC.
Please find below what I did so far (XMLvRPC, a LV version of XML-RPC)
(few slides here) and check also my contribution in the proceedings at PCaPAC06.
I wasn't my intention to be fully XML-RPC compliant, so I didn't go further.
luciano