XPath syntax error thrown when using evaluate() method - xslt-2.0

Question

Still i am getting the below error
Error at xsl:param on line 6 of file:/E:/saxon/parastyleText.xsl:
XPST0003: XPath syntax error at char 0 on line 6 in {...le/#w:val[matches(., c
oncat...}:
Invalid character '^' in expression
Failed to compile stylesheet. 1 error detected.
Modified XSL:
<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:ve="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships" xmlns:m="http://schemas.openxmlformats.org/officeDocument/2006/math" xmlns:v="urn:schemas-microsoft-com:vml" xmlns:wp="http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawing" xmlns:w10="urn:schemas-microsoft-com:office:word" xmlns:w="http://schemas.openxmlformats.org/wordprocessingml/2006/main" xmlns:wne="http://schemas.microsoft.com/office/word/2006/wordml">
<xsl:param name="styleName" select="'articletitle'"/>
<xsl:param name="tagName" select="'//w:p[w:pPr/w:pStyle/#w:val[matches(., concat('^(',$styleName,')$'),'i')]]'"/>
<xsl:output method="text"/>
<xsl:template match="/">
<xsl:value-of select="saxon:evaluate($tagName)" xmlns:saxon="http://saxon.sf.net/"/><xsl:text>
</xsl:text>
</xsl:template>
</xsl:stylesheet>
Please dont reply that, quotes will make 'tagName' as string and remove those quotes. This value will be actually passed from java as a string , tats y for testing purpose i have passed this xpath as string.

Answer 1

According to the online documentation http://www.saxonica.com/documentation9.1/extensions/functions.html Saxon 9.1 supports an evaluate function in the Saxon namespace http://saxon.sf.net/. So with Saxon 9.1 try <xsl:value-of select="saxon:evaluate($tagName)" xmlns:saxon="http://saxon.sf.net/"/>. Of course you can move the namespace declaration up to the xsl:stylesheet element if you want, I just put it on the xsl:value-of in this post for a short but complete sample of code.
Also note that with your variable named tagName it is likely that you simply have a single element name, in that case it might suffice to use <xsl:value-of select="*[local-name() eq $tagName]"/>.