XML as a string param

Hi,

Is it possible to pass XML as a string param into a stylesheet and then 
use xpath expressions on it?
What I am trying to do is to pass in the parameters from a 
ServletRequest (serialized as XML) into my XSL like this:
<xsl:param name="requestParams"/>

And then later on using it to fill in values with something like:

<xsl:value-of select="$requestParams/map/entry[key = 'param1']/value[0]" />

The xml string for the params looks like this:
<map>
   <entry>
         <key>param1</key>
         <value>val1</value>
         <value>val2</value>
   </entry>
   ...
</map>

BTW, I am using XSLT 2.0.

David Sinclair.