i think CEC doesnt require proof of funds like FSW (BUT CHECK AGAIN!). All I know is you will need to show bank statements of up to 6 months when making PR application
I just googled this:
http://www.cic.gc.ca/english/helpcentre/answer.asp?qnum=1145&top=29
As per the http://www.cic.gc.ca/english/helpcentre/answer.asp?qnum=1145&top=29
Just write in the letter of explanation that you are invited under CEC class so you do not need to show the funds. You can enter Zero in the amounts section.
You don't need to provide POF. fill zero in amount to get rid of POF place holder or upload LOE in place of POF that you don't need POF as you are invited under CEC