As I understand it, you cannot export company data file from QuickBooks Online edition into QuickBooks desktop in Canadian versions (Pro or Premier) at this time.
This is what they recommend, in case you are thinking of moving from QuickBooks desktop to QuickBooks Online edition.
When you export your company file to QuickBooks Online it creates a copy of your data. The company file on your computer (for QB desktop) remains intact so you can always go back.
Important Note: For your trial period, we recommend running both company files in conjunction with one another. Data from QuickBooks Online is not backwards compatible into QuickBooks Pro or Premier. So if you decide to go back to QuickBooks Pro or Premier, the data you have entered into QuickBooks Online will not carry over. Double entries will be required.