XSLT; parse escaped text to a node-set and extract subelements - xslt

Question

I've been fighting with this problem all day and am just about at my wit's end.
I have an XML file in which certain portions of data are stored as escaped text but are themselves well-formed XML. I want to convert the whole hierarchy in this text node to a node-set and extract the data therein. No combination of variables and functions I can think of works.
The way I'd expect it to work would be:
<xsl:variable name="a" select="InnerXML">
<xsl:for-each select="exsl:node-set($a)/*">
'do something
</xsl:for-each>
The input element InnerXML contains text of the form
<root><elementa>text</elementa><elementb><elementc/><elementd>text</elementd></elementb></root>
but that doesn't really matter. I just want to navigate the xml like a normal node-set.
Where am I going wrong?

Answer 1

In case you can use Saxon 9.x, it provides the saxon:parse() extension function exactly for solving this task.

Answer 2

what I've done is had a msxsl script in the xslt ( this is in a windows .NET environment):
<msxsl:script implements-prefix="cs" language="C#" >
<![CDATA[
public XPathNodeIterator parse(String strXML)
{
System.IO.StringReader rdr = new System.IO.StringReader(strXML);
XPathDocument doc = new XPathDocument(rdr);
XPathNavigator nav = doc.CreateNavigator();
XPathExpression expr;
expr = nav.Compile("/");
XPathNodeIterator iterator = nav.Select(expr);
return iterator;
}
]]>
</msxsl:script>
then you can call it like this:
<xsl:variable name="itemHtml" select="cs:parse(EscapedNode)" />
and that variable now contains xml you can iterate through