It appears that you are aware of this but I thought I'd just point out (for other monks' potential interest) that ALL Canadian postal codes follow the format XnX nXn where X is an alpha and n is a numeric character. And you are correct that the first digit in the code indicates the province (though whether that will truly indicate whether you want to use English or French is unclear as other parts of the country besides Quebec speak French.

To get the whole scoop on Canadian postal code system, you can get an entire PDF on the subject from Canada Post here. I hope this helps!

..Guv

PS update: wmono wants me to clarify that while the majority of Quebecers speak French, there is a sizeable English-speaking minority also.