File Management in ASP.NET C#

Question

Trying to make a new dimension to file management interface. I want a situation where files that's are 1wk old should be in a folder, same goes with 2wk old in a different folder same goes with 3 while greater than 4weeks in another folder .. This is exactly what i mean in a datagridview.

                *.Docx       *.Pdf       *.txt       *.xls       *.jpeg

<1Week             3         

2Week                          5

3Week                                      1

>4Week                                                 2


NB: The numbers represent number of files(docx,pdf,txt,xls) that are present and how old they are.

So clicking on the numbers the user gets the details of all the files and other file details. Would really appreciate any help on this.

Thanks in advance.