accessing paramters as node-sets

currently i'm accessing a xsl variable such as:

<xsl:variable name="test">
<some>xml</some>
</xsl:varialbe>

using exsl:node-set($test)

now I want to pass in the same xml as a paramter such as:

<xsl:param name="test2"/>

and then access it with exsl:node-set($test2) but it doesnt work.  Is this
possible?

Marcus