Exemptions for pre-University courses (Especially CEGEP) is managed at the Univ/Faculty level and is not administered by the department.
Please visit the following webpages for some information in that aspect.
https://www.mcgill.ca/transfercredit/prospective/cegep
https://www.mcgill.ca/transfercredit/faq
https://www.mcgill.ca/exams/dates/science
If you have an overalp between McGill (required ones) courses because of your program requirements, you are generally allowed to replace the credits for one of them using other complimentary courses. Please contact Liette (for CS). You may also have to coordinate with your undergraduate student affairs coordinator for your other program (e.g. Math).
If you are applying for transfer of credits for a course you took in a different university as part of your exchange, etc., then make sure that your external univ course is present in nimbus. If not present, submit a new request with the necessary information. The information you need to provide is described in the FAQ. It is important that you use the the system directly instead of emailing individuals for followup. This is because there are different levels of approvers, each of whom is evaluating a different aspect. Using a centralized system ensures that all of the documents and approvals are in place and can be reused by another person who is trying to transfer credits for the same course. If any of the approvers/reviewers find that a specific information is missing then they will mark the request as incomplete and you can upload the additional information requested and the process will continue.
Please DO NOT forward your "Transfer Credit Assessment Form" (Minerva) requests to me. I do not have the authority to approve them. You should consult your program coordinator to verify who can approve it.