title: Excel - Subtotal based on multiple columns
body: <p>I have an XLS with the following columns: Locations, Dates (dd/mm/yyyy), Amounts ($).
  I want to create another sheet in the workbook that will summarize the amounts by location and month so that I can see the total monthly per location, grand total monthly (vertical  monthly total, for all locations), and total annual (horizontal YTD for a location) and grand total annual (for all locations).</p>
  
  <p>Basically, create this report from the main spreadsheet:</p>
  
  <p>Location Jan    Feb...  Dec    Total YTD <br>
  Loc1   &nbsp;  &nbsp;$1000  $1000   $1500    $3500 <br>
  Loc2   &nbsp;  &nbsp;$3000  $1000   $500     $6500 <br>
  Loc3   &nbsp;&nbsp;  $2000  $1000   $2500    $7500 <br>
  ========================================<br>
  Total:   $6000  $3000...$4500    $17500  </p>
  
  <p>Any suggestions on how to achieve this? What functions to look into? </p>