How do I rename multiple files by counting up a fixed number?

[CrowBar]

Hello. I got around 2000 photos for players I need to adjust to the exact ID of my savegame.

To be exact, I need to add 4961 to each file name (for example: 2000 becomes 6961, 2005 becomes 6966, etc.)

Does anyone know how I can do this? The ID's are not all in order counting from one number. (for example; 6000, 6001, 6003, 6006) so it has to take that into account.

 

[wkdsoul]

Use excel to extract all the file names in order 
use formula to add 4961

Programme called file renamer should allow you to replace all the names now you have the before and after numbers

[CrowBar]

Thanks. I think I figured it out.