I mainly use Custom Exports rather than Customer Reports; however I thought I'd give your problem a try. I created a new custom report, one that had data that could be totaled. I then went into Design and in the Footer added a DB Calc box (15th icon from the left). The box that appeared showed "Sum(?)". I then went up to selection bar beneath the icons and used the drop down menu to select the Data I wished to be totaled. In my case, I selected "InvoiceTotal". I saved and then printed to PDF and found that the system did provide a total at the bottom of each page.

Let me know if you are able to figure it out. I do agree it would be nice if you could export to Excel but since that is not current feature, I think you'll have to pick between the two for what works best. I would most likely stick with Custom Exports, exporting to Excel and then create a Word file that I could make a "pretty" report for. Though maybe I'm thinking too hard and someone has a better suggestion.

Best -- Kim