passing xml string to xsl

Hi

I want to pass XML into XSL and then use it in templates.I've passed to my
XSL, XML string using xsl:param

<xsl:param name="VisibleColumnsConfigXML"/>

Now, in this parameter I've got XML string. I can display XML in
VisibleColumnsConfigXML parameter like this

<xsl:value-of select="$VisibleColumnsConfigXML"/>

But I want to access XML in VisibleColumnsConfigXML like node list, not
string. How to do it ?

MS