Here is a bit more information which I hope clarifies the need.

We are building 300+ reports. The reports consist of a chart and data tables. We believe we can build all 300+ reports from 5 to 7 designs.

The 300+ reports will be updated with new data each month.

While we are 90% done with report design, the last 10% could take another 3 to 4 weeks during which time we need to begin building the reports. We anticipate changes to be template of colors used, location of logo, sizing of page layout. Which means that if we can't autoupdate the reports going into each file and making the change....300+ times.

Ideally, we could build the 5 to 7 templates and lock down the design. Then for each report the only thing that could be modified is the data. If we had to make a change to the template it would be evident in the actual reports. We don't plan on creating monthly versions of the 300+ reports, but rather just changing the data and resaving. This is why we would need changes in the template to cascade down to the reports.