Rule from param and 2 Vals for keys

Hello,
Is it possible to invoke a select or test or other xpath query from
the value found within a variable or param?

So:

<xsl:call-template name="mytest">
  <xsl:with-param>/root/document[@name='monkeys']"</xsl:with-param>
</xsl:call-template>

<xsl:template name="mytest">
  <xsl:param name="test">/root/document[@name='monkeys']"</xsl:param>

  <xsl:if test="$test">PASS</xsl:if>

</xsl:template>

- ALSO - 

How can you create a key for the following, where "ABC" and "XYZ" and
"xxx" are all the values I'd like to supply to the key for matching:

/root/recordset[@rsName='ABC']/record[field[@fieldname='DEF'] = 'xxx']