Terms of Service checkbox ONLY for use in single post

I am teaching an e-course here:

http://family.practicerecovery.com/courses/transforming-our-suffering/

Before people are able to login with their username and password I would like for them to have to check a box upon login that they agree to the terms of service. I only want them to have to do this once.

Is this possible with this plugin? I'm a little confused how to get it to work.