const regex = /(?:(?!<(?:field|exclGroup)(?!\w)(?>"[\S\s]*?"|'[\S\s]*?'|(?:(?!\/>)[^>])?)+>)[\S\s])*(?><(field|exclGroup)(?=(?:[^>"']|"[^"]*"|'[^']*')*?\sname\s*=\s*(?:(['"])([\S\s]*?)\2))\s+(?>"[\S\s]*?"|'[\S\s]*?'|(?:(?!\/>)[^>])?)+>)(?:(?&core)|)<\/\1\s*>(?:(?!<(?:field|exclGroup)(?!\w)(?>"[\S\s]*?"|'[\S\s]*?'|(?:(?!\/>)[^>])?)+>)[\S\s])*(?(DEFINE)(?<core>(?>(?><([\w:]+)(?>"[\S\s]*?"|'[\S\s]*?'|(?:(?!\/>)[^>])?)+>)(?:(?&core)|)<\/\5\s*>|(?!<\/[\w:]+\s*>)(?>[\S\s]))+))/g;
// Alternative syntax using RegExp constructor
// const regex = new RegExp('(?:(?!<(?:field|exclGroup)(?!\\w)(?>"[\\S\\s]*?"|\'[\\S\\s]*?\'|(?:(?!\\\/>)[^>])?)+>)[\\S\\s])*(?><(field|exclGroup)(?=(?:[^>"\']|"[^"]*"|\'[^\']*\')*?\\sname\\s*=\\s*(?:([\'"])([\\S\\s]*?)\\2))\\s+(?>"[\\S\\s]*?"|\'[\\S\\s]*?\'|(?:(?!\\\/>)[^>])?)+>)(?:(?&core)|)<\\\/\\1\\s*>(?:(?!<(?:field|exclGroup)(?!\\w)(?>"[\\S\\s]*?"|\'[\\S\\s]*?\'|(?:(?!\\\/>)[^>])?)+>)[\\S\\s])*(?(DEFINE)(?<core>(?>(?><([\\w:]+)(?>"[\\S\\s]*?"|\'[\\S\\s]*?\'|(?:(?!\\\/>)[^>])?)+>)(?:(?&core)|)<\\\/\\5\\s*>|(?!<\\\/[\\w:]+\\s*>)(?>[\\S\\s]))+))', 'g')
const str = `<field xmlns="http://www.xfa.org/schema/xfa-template/2.8/" y="0in" x="0.343mm" w="8.881pt" h="9.108pt" name="detcon_recreation_only">
<ui>
<checkButton size="8.881pt">
<border>
<edge stroke="lowered"/>
<fill/>
</border>
</checkButton>
</ui>
<font size="0pt" typeface="Adobe Pi Std"/>
<para vAlign="middle"/>
<value>
<text>0</text>
</value>
<items>
<text>1</text>
<text>0</text>
<text/>
</items>
</field>
<field xmlns="http://www.xfa.org/schema/xfa-template/2.8/" name="detcon_special_housing" y="5.393mm" w="27.94mm" h="4.134mm" x="0.343mm">
<ui>
<choiceList>
<border>
<edge stroke="lowered"/>
</border>
<margin/>
</choiceList>
</ui>
<font typeface="Arial Narrow" size="6pt"/>
<margin topInset="0mm" bottomInset="0mm" leftInset="0mm" rightInset="0mm"/>
<para vAlign="middle"/>
<value>
<text>NA</text>
</value>
<items>
<text>Not Applicable</text>
<text>Hotel Component</text>
</items>
<items save="1" presence="hidden">
<text>NA</text>
<text>HC</text>
</items>
</field>
<exclGroup xmlns="http://www.xfa.org/schema/xfa-template/2.8/" name="detcon_photo_taken" x="0in" y="0in">
<?templateDesigner itemValuesSpecified 1?>
<field w="12.446mm" h="3.825mm" name="lb_yes">
<ui>
<checkButton size="1.7639mm" shape="round">
<border>
<?templateDesigner StyleID apcb1?>
<edge/>
<fill/>
</border>
</checkButton>
</ui>
<font typeface="Myriad Pro"/>
<margin leftInset="1mm" rightInset="1mm"/>
<para vAlign="middle"/>
<caption placement="right" reserve="7.698mm">
<para vAlign="middle" spaceAbove="0pt" spaceBelow="0pt" textIndent="0pt" marginLeft="0pt" marginRight="0pt"/>
<font size="8pt" typeface="Arial Narrow" baselineShift="0pt"/>
<value>
<text>YES</text>
</value>
</caption>
<value>
<text xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:nil="true"/>
</value>
<items>
<text>1</text>
</items>
</field>
<field w="28.702mm" h="3.825mm" name="lb_no" x="13.233mm">
<ui>
<checkButton size="1.7639mm" shape="round">
<border>
<?templateDesigner StyleID apcb1?>
<edge/>
<fill/>
</border>
</checkButton>
</ui>
<font typeface="Myriad Pro"/>
<margin leftInset="1mm" rightInset="1mm"/>
<para vAlign="middle"/>
<caption placement="right" reserve="23.954mm">
<para vAlign="middle" spaceAbove="0pt" spaceBelow="0pt" textIndent="0pt" marginLeft="0pt" marginRight="0pt"/>
<font size="8pt" typeface="Arial Narrow" baselineShift="0pt"/>
<value>
<text>NO (see comments)</text>
</value>
</caption>
<value>
<text xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:nil="true"/>
</value>
<items>
<text>0</text>
</items>
</field>
<border>
<edge presence="hidden"/>
</border>
<?templateDesigner expand 1?></exclGroup>`;
const subst = `VALUES (12345,"$3","/Tx", "", "N", "Y"),\r\n`;
// The substituted value will be contained in the result variable
const result = str.replace(regex, subst);
console.log('Substitution result: ', result);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions