I asked the same question and was given this link....
http://vbcity.com/forums/faq.asp?fid=8&cat=DataReport&#TID18311
it actually works just fine for what you want to do, but I need to get a start date and end date from the users and have the report show all records between those two dates. I can't for the life of me figure out how to pass 2 parameters on the same field....Seems to me that this would be a very common need for a report, (i.e. to show a range of invoices)...
Hope the link helps you at least.