I am <xsl:sort>ing elements and then using <xsl:apply-templates
select=".">.  I need to set the @mode attribute of
<xsl:apply-templates>, with a value from the XML.  As @mode takes a
qname, not an expression, I cannot reference a variable (set a
variable with <xsl:value-of> and call $var_name), reference a node (
self::node()/@my_attribute), or call a function (
current()/@my_attribute or id() or key() ).  Is there any way I can
accomplish this?

-Stephen