title: Dynamic version of vb SelectSingleNode
body: <p>I know that with</p>
  
  <pre><code>book = root.SelectSingleNode("descendant::bk:book[bk:author/bk:last-name='Atwood']", nsmgr);
  </code></pre>
  
  <p>it is possible to adress elements inside a xml file in a static manner.</p>
  
  <p>Is there a way to use a similar scheme but with dynamic adressing. E.g. where'Atwood' is not a const string rather than a dynamic string.</p>
  
  <p>Thanks for helping.</p>
  
  <p>Btw: Example from <a href="https://msdn.microsoft.com/de-de/library/system.xml.xmlnode.selectsinglenode(v=vs.110).aspx" rel="nofollow">Microsoft help site</a></p>