Thanks for the information. What I am going to do for the moment is just write something that computes the percentage for me and have TAs update it every week on canvas. You can easily get the date by going to the score option under the achievements page. I definitely don't have enough time and experience to get this working at the moment.
It would be nice to make it work automatically and be able to link it to canvas like a homework or quiz though, if it ever gets implemented in some release. My plan is to give bonus points for achievements.