Looks like I found a way -- kind of convoluted, but it works: Use <xsl:text 
disable-output-escaping="yes"><![CDATA[ . . . ]]></xsl:text>

<xsl:template name="foo">
<xsl:text disable-output-escaping="yes"><![CDATA[
  <pkg:part pkg:name="/docProps/custom.xml" 
pkg:contentType="application/vnd.openxmlformats-officedocument.custom-properties+xml" 
pkg:padding="256">
   <pkg:xmlData>
    <Properties 
xmlns="http://schemas.openxmlformats.org/officeDocument/2006/custom-properties" 
xmlns:vt="http://schemas.openxmlformats.org/officeDocument/2006/docPropsVTypes">
     <property fmtid="{{D5CDD505-2E9C-101B-9397-08002B2CF9AE}}" pid="2" 
name="Customer">
      <vt:lpwstr>]]></xsl:text>
       <xsl:value-of select="/my:myFields/my:Project"/>
      <xsl:text disable-output-escaping="yes"><![CDATA[</vt:lpwstr>
     </property>
    </Properties>
   </pkg:xmlData>
  </pkg:part>
]]></xsl:text>
</xsl:template>
-- 
Greg Collins
Microsoft MVP
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