The detail section is printed once for every row in the data source similarly to a repeater and this happens vertically. The columns actually represent the separate pages of the report, which are treated as logical pages rendered on the same physical page. Columns are arranged from left to right, top to bottom, and are separated by white space between each, and data flow in the columns is top to bottom, left to right. If the report is divided into more than one column, each physical page is divided vertically into columns, each of which is considered a logical page. The easiest way to visualize this is imagining the columns in a newspaper.
So in short there is no straight-forward approach, but you can handle this scenario with some manual preparation of the data and our agile CrossTab item. We have prepared a sample project and video showing how to accomplish this task. Please review the attachments and let us know if you need further assistance.
the Telerik team
Q3’11 of Telerik Reporting is available for download. Register for the What's New in Data Tools webinar to see what's new and get a chance to WIN A FREE LICENSE!