A much more efficient idea is to not have an income tax refund. Any refund you are getting is simply due to paying too much in over the year. No matter how you slice it, it is an interest free loan to the government. 

Any systematic RRSP deposit program qualifies for a reduced withholding tax requirement. If you are getting any substantial refund it is a sure sign that you are doing something wrong.

Your payroll department will know how to fix it.

Once that is done, make sure that your extra "net" pay is used properly.