title: Excel DSum (possibly another way)
body: <p>I have a costing spreadsheet for personal use. Each cost is categorised by a value selected from a 'Categories' list. So far so good.</p>
  
  <p>I want to make a summary which shows total costs for each category. I was thinking of using DSum but cannot get it to work.</p>
  
  <p>Let me explain better: consider the below example</p>
  
  <p>Main List:</p>
  
  <pre><code>Date    Category          Cost
  ----    --------          ----
  01/Jul  Book              20.00
  03/Jul  Stationery         2.00
  05/Jul  Book              15.00
  </code></pre>
  
  <p>Summary:</p>
  
  <pre><code>Category          Cost
  --------          ----
  Book              35.00
  Stationery         2.00
  </code></pre>
  
  <p>Any help or pointers to a solution appreciated on how to do summary.</p>
  
  <p>Thanks</p>