on the database expert, above your table should be a line, Add Command, or something like that. When you click on it, you can enter SQL retrieve data. In your case, you need to 'create' data, since it doesn't exist in the database (at least not in a way that Crystal is looking for it). Off-hand, nothing is coming to me on how to select a range of dates, but I am sure that their is something on line.
I get all of my data from stored procedures, and if I need 'extra' data, I create it there.
HTH