title: Excel Indirect function to external workbook - REF! result
body: <p>I was writing a function to link indirectly to an external workbook and I came up with this:</p>
  
  <pre><code>=+INDIRECT("=+'"&amp;$W$2&amp;"\"&amp;$Y$4&amp;"\"&amp;$X$4&amp;"\["&amp;$W$4&amp;"]"&amp;MID($W$4,1,LEN($W$4)-4)&amp;"'!"&amp;$U$15)
  </code></pre>
  
  <p>That though returns <code>#REF!</code> as result</p>
  
  <p>The part within the () brackets, when evaluated return the following:
    <code>"=+'C:\Folder0\Folder1\Folder2\Folder3\Folder4\Folder5\Folder6\Folder7\Folder8\
  [MyFile.csv]NameTab'!$D$2"</code></p>
  
  <p>and if I were to use it directly in a cell (once evaluated) would work</p>
  
  <p>Could someone help me understand what is wrong here?</p>