How do you re enroll user that failed certification course?

I am just starting to use captivate prime for educating our internal employees.

One of the users failed one of the courses of the certification course, and I would like to re enroll them without needing to delete them as a user.  I don't want to give the users infinite attempts at passing, but I would like the ability to re enroll them at my discretion.  Is there a way to do this?

Thanks,

Chris