title: Adding previous cell and current cell functions
body: <p>I like to have an Excel Function for:  </p>
  
  <pre><code> Previous cell + Current Cell  = Current cell  
  </code></pre>
  
  <p>to do this function for the entire row,  when I enter a new value each time, Eg. <code>A1+A2= A2</code>.</p>