Thanks to both of you. So many things to learn ... so little time.
Mark

> I don't understand regex

It's really really really really worth learning, and not as difficult as
it might at first appear.

Here is a tutorial,
http://www.regular-expressions.info/tutorial.html

a reference
http://www.regular-expressions.info/reference.html

and a regexp flavour comparison:
http://www.regular-expressions.info/refflavors.html

In the context of XML processing you will most likely be interested in the
two most right columns of the table,
XML Schema Regular Expressions,
XQuery and XPath Regular Expressions,

Hermann Stamm-Wilbrandt
Level 3 support for XML Compiler team, Fixpack team lead
WebSphere DataPower SOA Appliances
https://www.ibm.com/developerworks/mydeveloperworks/blogs/HermannSW/
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I don't understand regex

It's really really really really worth learning, and not as difficult as
it might at first appear.

--
Liam Quin - XML Activity Lead, W3C, http://www.w3.org/People/Quin/
Pictures from old books: http://fromoldbooks.org/