the ‚Group by Sequence‘ feature allows you to form groups of (sequential) images with same properties. For example, you can put an exif field containing the used lens in the ‚Seq. Property‘ field and it will create a new group whenever you have switched the lens on your camera. The resulting group names have to be entered manually.
ATM, the easiest way to achieve what you want, would be to use a ‚Keyword‘ step, and enter the numbers manually. I’ll take a look to see if there is a easier method …..