Teacher override self-selected flex activity#1992

When a student has signed up for a flex activity, but then a teacher needs to assign that student to a specific flex activity, the student sees both activities on his end…the one he signed up for and the one the teacher assigned him to. Is there a way for the teacher to override the student’s choice so that he is “locked into” the flex activity that the teacher assigned to him? Example: the teacher “locks” a student into a study/work room because of missing assignments.