The company should provide two documents for sponsorship. One giving a description of you as an employee and the reasons for sponsorship and detailing that your job will be available when you return and how the studies will benefit your post.
Secondly a letter of financials. How much the company will provide. How they will provide the funds. A bankers draft in convertible currency is most efficient. They'll need to cover most of, if not all of your tuition. Unless you have proof that you can cover the remainder. You need tuition plus 10,000 plus travel expenses. Letters from the company should be legit, on a company letterhead. signed and have their contact info.
The program you want to study should be higher than the credentials you already have and should be reasonable in light of your profession and previous qualifications.
Show additional ties to your country such as a bank account, housing and close family
Write a letter of explanation, be honest clear and precise. Doesn't have to be all professional. Just an outline of your goals and what you're trying to do and how your documents are linked, make everything make sense. always drop a line about returning home to your country. do not mention anything about working or living in canada.