How to copy every N file when serialization is not consistent

I have a directory containing 101695 files ranging from img001.jpg to img101693.jpg and I want to move every 100th image to another directory. I have found some similar posts such as https://unix.stackexchange.com/questions/59089/how-to-copy-every-4th-file-in-a-folder but those assume that the number of digits in the serial is the same in all files so my range would need to start with img000001.jpg Is there a way to do this or do I need to modify my file names so that they all have the same number of characters in the serial?