> Is it possible to invoke a template match passing an arbitrary
> parameter?

yes, just use xsl:with-param (in xslt2 you may also want to look at
tunnel parameters)

> if should be possible reset a variable value,

not sure what you mean by that, but each time you call a template you
can bind values to all it's parameters with xsl:with-param

on t heparemt of elem2 you want

<xsl:template match="something">
   <xsl:apply-templates>
      <xsl:with-param name="x" select="hgvf"/>
</xsl:apply-template>


David

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