For learners, is there a way to restrict their access to a course or activity, unless they have booked themselves in for a seminar?

We want our employees to have access to pre-learning, prior to attending a face-to-face session, but don't want them to have access to the pre-learning unless they're booked in for a face-to-face session.

Can this be facilitated in the course itself (without needing the attendance to be marked), or in a program? That the seminar booking is a separate course to the pre-learning course?

Help is appreciated! 

Thanks