Grouping separator

      <xsl:stylesheet
                  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
                  version="2.0">
            <xsl:output  method="xml"
                        indent="yes"
                        omit-xml-declaration="yes"/>

            <xsl:template  match="/aaa">
                  <aaa>
                        <xsl:value-of  select="format-number(123456789,'###,###')"/>
                  </aaa>
                  <bbb>
                        <xsl:value-of  select="format-number(123456789,'##,##')"/>
                  </bbb>
                  <ccc>
                        <xsl:value-of  select="format-number(12345,'0000,00')"/>
                  </ccc>
                  <ddd>
                        <xsl:value-of  select="format-number(12111.34522,'#,###.######')"/>
                  </ddd>
            </xsl:template>

      </xsl:stylesheet>

      <aaa/>

      <aaa>123,456,789</aaa>
      <bbb>1,23,45,67,89</bbb>
      <ccc>01,23,45</ccc>
      <ddd>12,111.34522</ddd>