Calculating Monthly & Weekly Performance.

Example:

Let me try to explain my problem.
I need to publish Weekly Performance & Monthly Performance of the project on daily basis.
We have a Daily Performance Report from where I had to manually collate data of all the days in order to publish the above mentioned report.
For eg: A report that I'm publishing on 16th feb will have data till 16th, so in order to prepare the report I had to open all the 16 Performance report and manually copy data.
Is there a way I can a extract data from all the 16 daily reports in the New Workbook.

Please suggest.

All daily reports are saved at the same location i.e. C:\Feb
Each DPR has a unique name i.e. DPR Feb 1 2012, DPR Feb 2 2012, DPR Feb 3 2012.......and so on.