Thanks Pradeep,
We have got there now!
I have
declare namespace ns1='http://sword-insurance.com/openplus/documentservice';
//ns1:Document[1]
for the declaration
and (using the Select from current option and replacing actual values with wildcards)
<Document DocumentKey='*' DocumentType='*' FileName='*' xmlns="http://sword-insurance.com/openplus/documentservice" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:wsa="http://schemas.xmlsoap.org/ws/2004/08/addressing" xmlns:wsse="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd" xmlns:wsu="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd">
<File>*</File>
</Document>
I have Allow Wildcards checked and Ignore namespace prefixes unchecked (checking it gave another error).
Thanks very much for your help
Richard