title: Using Excel sumifs to sum matrix elements
body: <p>Is it possible using Excel's sumifs to find the sum of elements of a matrix using condition on row and column? For example matrix:</p>
  
  <pre><code>    c   d   e
  a   1   2   3
  b   4   5   6
  </code></pre>
  
  <p>I would like to sum elements of b row, d and e columns. The solution should work also for large dimension matrix. Sorry for ugly formatting.</p>