I can think of a few things that might help here.
For one, if it's just a simple count aggregation from your query results, then make sure you have toggled on the Summary Footer Panel on your data grid, and right-click below the column you want to aggregate values for, then choose your aggregation metric (COUNT in your case). See screen capture #1 below.
Two, you can right click on your data results grid and bring up the Data Report Wizard. The wizard asks you if you want to aggregate on any of the columns you chose to report on. See screen capture #2 below.
Finally, like most software vendors, Quest embeds third-party solutions in many of its products, and the Report Writing capabilities are one of them, so probably not as much "training" emphasis on these components as on the Toad product itself. However, you'll find the following links useful:
That last link points to a page from which you can access user guides and documentation for Toad's embedded report writer. Hope this helps!