1. Ask UBC to create the alias Firstname.Lastname@ubc.ca for your FASmail account, when done log in to https://mail.ubc.ca/.
2. Create an Inbox rule (go to the little gear wheel on the top right of the web interface www.mail.ubc.ca) to have FASemail forwarded to @stat.ubc.ca
3. Split the rule into two: one to forward emails only, and another one to delete the forwarded emails, and make sure the "delete" rule is set up after the forward one.
4. If you don't do 3 above, you will have your "alias" email forwarded, but email to your CWL@mail.ubc.ca will disappear in thin air
5. With 3, all my FASmail (those sent to CWL@mail.ubc.ca and also those sent to Firstname.Lastname@ubc.ca) get forwarded to @stat.ubc.ca
Here is the UBC IT Howto: https://web.it.ubc.ca/forms/fasmail/