declare @X xml = '

<row id="1000000" xml:space="preserve">

<c1>Exported</c1>

<c2>Text Sample 1</c2>

<c2 m="2">Text Sample 2</c2>

<c2 m="3">Text Sample 3</c2>

<c2 m="4">Text Sample 4</c2>

<c3>Text Sample 1</c3>

<c3 m="2">Text Sample 2</c3>

<c3 m="3">Text Sample 3</c3>

<c4>Text Sample</c4>

<c5>Text Sample</c5>

</row>';

set @X.modify('insert <ctest>New Added</ctest> after (row/c3)[last()]');