meter html in XSL

I am writing an XSL file and the question I have is if I can modify the values of html with variables xsl, for example

<div id="menu">
<ul>
<xsl:for-each select="recursos/infoCategoria/descendientes/categoria">
    <xsl:sort select="nombre" order="ascending"/>


        <li><a href="#C1" title="ir a "> <xsl:value-of select="(nombre)"/> 
        <xsl:for-each select="recursos/recurso"></xsl:for-each></a></li>



    </xsl:for-each>
</ul>
</div>

On the line:

<li><a href="#C1" title="ir a "> <xsl:value-of select="(nombre)"/>

"# c1" I want to replace it with a variable that I have defined in xsl, can it be done so that the html remains valid ?, I try to do it with but then when viewing the html it only leaves text and the html is not valid