Add a new sibling node after matching attribute value - xslt

Question

I need to add a node after a template match.
The template match is on an attribute value, based on a parameter.
I have been successful at adding the node as a child of the matched attribute. However, I need the added node to be a sibling node, not a child node.
Is there a way to add the note as a sibling, not as a child of the matched attribute?
This is my xml file:
<WORK SRCDBID="DBIDxx" DSTDBID="SERVER" WORKTYPE="DELTA" SETNUMBER="1">
<TXID SRCDBID="DBIDxx" CPDATE="2021200932651" TYPE="0">
<OP ACTION="I" TBL="RTD-WORKORDER">
<COLS>
<COL NAME="WoNum" VAL="303105525"/>
<COL NAME="NumWoLin" VAL="1"/>
<COL NAME="LinNum" VAL="1"/>
<COL NAME="RtrdTag" VAL="527395802"/>
</COLS>
</OP>
</TXID>
</WORK>
My failing result:
<WORK SRCDBID="DBIDxx" DSTDBID="SERVER" WORKTYPE="DELTA" SETNUMBER="1">
<TXID SRCDBID="DBIDxx" CPDATE="2021200932651" TYPE="0">
<OP ACTION="I" TBL="RTD-WORKORDER">
<COLS>
<COL NAME="WoNum" VAL="303105525"/>
<COL NAME="NumWoLin" VAL="1"/>
<COL NAME="LinNum" VAL="1"/>
<COL NAME="RtrdTag" VAL="527395802">
<COL NAME="DuplicateTag" VAL="0303105525|31"/>
</COL>
</COLS>
</OP>
</TXID>
</WORK>
My desired result:
<WORK SRCDBID="DBIDxx" DSTDBID="SERVER" WORKTYPE="DELTA" SETNUMBER="1">
<TXID SRCDBID="DBIDxx" CPDATE="2021200932651" TYPE="0">
<OP ACTION="I" TBL="RTD-WORKORDER">
<COLS>
<COL NAME="WoNum" VAL="303105525"/>
<COL NAME="NumWoLin" VAL="1"/>
<COL NAME="LinNum" VAL="1"/>
<COL NAME="RtrdTag" VAL="527395802"/>
<COL NAME="DuplicateTag" VAL="031123123|31"/>
</COLS>
</OP>
</TXID>
</WORK>
My xsl:
Parameter values are:
rtdTag = "527395802"
rtdDupTag = "0303105525|31"
<xsl:stylesheet version="2.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output indent="yes" media-type="text/xml" method="xml" />
<xsl:param name="rtdTag" />
<xsl:param name="rtdDupTag" />
<!-- This is the default template that copied everything -->
<xsl:template match="#* | node()">
<xsl:copy>
<xsl:apply-templates select="#* | node()"/>
</xsl:copy>
</xsl:template>
<!-- This is the "override" template for specific elements that match the passed in tag. -->
<xsl:template match="#*[. = $rtdTag]">
<!-- Copy the element everything inside it -->
<xsl:copy>
<xsl:copy-of select="node()"/>
</xsl:copy>
<!-- Add new node -->
<xsl:element name="COL">
<xsl:attribute name="NAME">
<xsl:text>DuplicateTag</xsl:text>
</xsl:attribute>
<xsl:attribute name="VAL">
<xsl:value-of select="$rtdDupTag"/>
</xsl:attribute>
<xsl:apply-templates/>
</xsl:element>
</xsl:template>
</xsl:stylesheet>

Answer 1

Change your template to match on the element that has that attribute, and then add your new element after copying that element.
<xsl:stylesheet version="2.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output indent="yes" media-type="text/xml" method="xml" />
<xsl:param name="rtdTag" />
<xsl:param name="rtdDupTag" />
<!-- This is the default template that copied everything -->
<xsl:template match="#* | node()">
<xsl:copy>
<xsl:apply-templates select="#* | node()"/>
</xsl:copy>
</xsl:template>
<!-- This is the "override" template for specific elements that match the passed in tag. -->
<xsl:template match="*[#* = $rtdTag]">
<!-- Copy the element everything inside it -->
<xsl:copy>
<xsl:apply-templates select="#*|node()"/>
</xsl:copy>
<!-- Add new node -->
<xsl:element name="COL">
<xsl:attribute name="NAME">
<xsl:text>DuplicateTag</xsl:text>
</xsl:attribute>
<xsl:attribute name="VAL">
<xsl:value-of select="$rtdDupTag"/>
</xsl:attribute>
</xsl:element>
</xsl:template>
</xsl:stylesheet>
And if you know the names of the element and attribute statically, I prefer element and attribute literals instead of using xsl:element and xsl:attribute:
<xsl:stylesheet version="2.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output indent="yes" media-type="text/xml" method="xml" />
<xsl:param name="rtdTag" />
<xsl:param name="rtdDupTag" />
<!-- This is the default template that copied everything -->
<xsl:template match="#* | node()">
<xsl:copy>
<xsl:apply-templates select="#* | node()"/>
</xsl:copy>
</xsl:template>
<!-- This is the "override" template for specific elements that match the passed in tag. -->
<xsl:template match="*[#* = $rtdTag]">
<!-- Copy the element everything inside it -->
<xsl:copy>
<xsl:apply-templates select="#*|node()"/>
</xsl:copy>
<!-- Add new node -->
<COL NAME="DuplicateTag" VAL="{$rtdDupTag}"/>
</xsl:template>
</xsl:stylesheet>