This is a very interesting question, and to the best of my knowledge there is no easy answer, and this is because the DataSource settings would need to be able to be changed on the fly, which is not currently doable.
However, if the files that are generated have some macro functionality for this, or other form of automation, would it not be a possibility to just have the records be pivoted upon finalization, so that you get the CostCenters as part of the rows instead?
Where are you exporting the files from? If its from a Database using some sort of query then there should be a pivot function that can be leveraged.