How do I insert an XSL processing instruction in a string?

As the subject says, how do I insert a processing instruction in a string?

I need to be able to construct an HTML anchor on the fly via XSL, along the
 lines of:

<A name="docname#<xsl:eval>ancestorChildNumber("CHAPTER",
(this))</xsl:eval>"></A>

Regards

Julian Burman



 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list