I have multiple, large sets of files. Each set is in one of the following formats:

ABC123-ABCDEFGHIJKLMNOPQRSTUVWXYZ.EXT

ABC1234-ABCDEFGHIJKLMNOPQRSTUVWXYZ.EXT

ABC12345-ABCDEFGHIJKLMNOPQRSTUVWXYZ.EXT

The first 3 alphanumerics (ABC) can be any three letters - sometimes capitalized and sometimes not.

The numbers (123, 1234, or 12345) that follow the first 3 alphanumerics can be any 3, 4, or 5 digit number.

The alphanumerics that follow (ABCDEFGHIJKLMNOPQRSTUVWXYZ) the 3, 4, or 5 digit number can be any combination of numbers and letters of variable length.

The file extension is always 3 alphanumerics and can contain 3 letters or 2 letters and a number.

If someone would be so kind, I need a RegEx that will convert the 3 digit and 4 digit numeric to a 5 digit numeric by adding the appropriate 2 or 1 zeroes, respectively. So, ABC123-ABCDEFGHIJKLMNOPQRSTUVWXYZ.EXT would become ABC00123-ABCDEFGHIJKLMNOPQRSTUVWXYZ.EXT and ABC1234-ABCDEFGHIJKLMNOPQRSTUVWXYZ.EXT would become ABC01234-ABCDEFGHIJKLMNOPQRSTUVWXYZ.EXT.

Many thanks!

P.S. I tried to figure it out and after an hour, I was as lost as when I started. Ha.