Renaming files

I am looking for a program or application that I can use to rename a large number of files in batch mode.

I have 5 folders, each containing about 800 .tif files. The file names consist of a few letters followed by a 3 digit number. I need to combine them all into one folder but I can’t because the file names are identical in each of the 5 folders.

I am looking for an application that can extract the 3 numbers, add a letter in front of the number and then rename the file, i.e.” A592”. I would use a different letter for the files in each of the 5 folders. Once they are renamed, they can then be combined into one folder. It is imperative that the 3 numbers in the new name remains the same as the original name because they relate to other fields in a database. The original numbers are not sequential; there are several numbers missing in each folder.

Any suggestions would be appreciated.

I have not used this myself but it's part of Microsoft's new Powertoys