<xsl:variable name='Name.re'
	      select='"\$\i\c*"'/>

 <xsl:analyze-string
	  select="@select"
	  regex="{$Name.re}"
	  flags="x">
	<xsl:matching-substring>

<xsl:value-of select="regex-group(0)"/>
etc

Thanks to those who offered help.
I owe you (another) beer Tony.

--
Dave Pawson
XSLT XSL-FO FAQ.
http://www.dpawson.co.uk