POF can be in any currency , along with it take the current currency exchange to CAD and do mention in the summary of POF. Take also note of currency fluctuation while giving POF otherwise the VO would again ask for fresh proof of POF.
Convert your currency to CAD $ on Yahoo Forex or
http://www.xe.com/ucc/Then make a cover letter giving the Amount converted to CAD...LIKE:
In my account in Bank xyz;
10,000USD = 10,276.50 CAD AS per Xe.com, Dated 07-01-2012 at 11.12PM