allow swap between sections but prevent drop

We have a few classes which are defined as needing Dept Consent to drop on the Curriculum Management, then selectSchedule of Classes, then selectSchedule New Course, then selectEnrollment Cntrl page.  This results in the students having to obtain consent when they want to swap sections of the same course.  Is there a way to define classes so that students can use self service to swap sections as long as they stay enrolled in the same course, but they are prevented from dropping the class or swapping it for a different course?