Escaping special characters

      <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">
                  <xxx>
                        <xsl:value-of  select="replace(.,'(\d+)\*(\d+)\?(\d+)','$2')"/>
                  </xxx>
                  <yyy>
                        <xsl:value-of  select="replace(.,'(\d+).*(\d+)\S?(\d+)','\$$2')"/>
                  </yyy>
                  <zzz>
                        <xsl:value-of  select="replace(.,'(\d+).*?(\d+).*?(\d+)','\$$1\\\$$2\\\\\$$3')"/>
                  </zzz>
            </xsl:template>

      </xsl:stylesheet>

      <aaa>111*222?33</aaa>

      <xxx>222</xxx>
      <yyy>$3</yyy>
      <zzz>$111\$222\\$33</zzz>