Let me share a few details about the sequential numbers on the check in QuickBooks Desktop.
QuickBooks Desktop uses numerical digits and automatically sequences your check number depending on what you first entered, regardless of the characters in it. The option that you're looking for hasn't been made available at this time.
We're always looking for ways we can make the software better for all users. By sharing your idea here in the Community, our app developers are pushing the envelope to improve the product's features to meet your needs.
For now, I suggest checking out regularly for any updates and enhancements through this link: Firm of the Future.
That should do it. I'm always around if you have any other concerns. Just make sure to leave a comment below. Have a wonderful day.