title: Add common prefix to all cells in Excel
body: <p>I have a column with some text in each cell.<br>
  I want to add some text, for example "X", at the start of all cells. For example:</p>
  
  <pre><code>A             B
  -----  &gt;&gt;&gt;&gt;  ----
  1            X1
  2            X2
  3            X3
  </code></pre>
  
  <p>What is the easiest way to do this?</p>