Is it possible to set the mode dynamically?

The use case:

1. Setting a variable to a file name

<xsl:variable name="PayloadName" select="/POM/Netflix/@payload" />

2. Using that variable to load the file dynamically into another variable

<xsl:variable name="payload" select="document(concat($PayloadName,
'.xml'))/payloadb/>

3. Calling a template and passing the file name as as a param to be used in
that called template as the mode.

 <xsl:call-template name="create-html-tables">
      <xsl:with-param name="PayloadName" select="$PayloadNameb/>
</xsl:call-template>

 <xsl:template name="create-html-tables">
        <xsl:param name=bPayloadName"/>
       <xsl:apply-templates select="$pom//Event" mode=b$payloadNameb/>
</xsl:template>

Is that a possibility in anyway shape or formb&? Otherwise I am thinking the
only alternative would be to use a choose and then hardcode the mode - which
works, but just wondering if there was a cleaner way?

<xsl:choose>
    <xsl:when test="$PayloadName = 'pivot-table-payload'">
        <xsl:apply-templates select="$pom//Event" mode="pivot-table"/>
    </xsl:when>
    <xsl:otherwise>
        <xsl:apply-templates select="$pom//Event" mode="default"/>
    </xsl:otherwise>
</xsl:choose>

Many thanks,

Rusty