title: use xslt to create tag in in parent node
body: <p>Suppose I have an XML document something like this (note that for my purposes, the order the tags appear in the final document doesn't matter, in case that makes a difference; we're just using XML as a fancy key/value pair contraption)</p>
  
  <pre><code>&lt;MyRoot&gt;
   various tags here I don't care about at the moment
   &lt;child&gt;&lt;GoldenTag&gt;1234&lt;/GoldenTag&gt;&lt;/child&gt;
  &lt;/MyRoot&gt;
  </code></pre>
  
  <p>Note that the value of GoldenTag is not always 1234; this was just for illustration.  Now, I want to create a SilverTag that is a (direct) child of MyRoot, whose value is the same as GoldenTag, assuming that GoldenTag exists and various other conditions are met.</p>
  
  <p>I see no good way to do this, because if I use <code>template mach='GoldenTag'</code> then the contents of the template ends up inside the <code>child</code> tag which is not where I want it.</p>