Hi Jawad,
I think I had replied u on this somewhere earlier. Anyway, plz note that as I left Dubai (May-2010) there was only one Forex House, Al Fardan Exchange, which was still making the CAD drafts. I got mine made from their Deira Br. - knew their Br. Manager, who gave me smarter rates than market.
U just have to go there, bargain a little with the counter staff, get the rates, convert your Dhs., pay the amount & u get the draft - on the spot. Remember, the drafts r drawn on BMO-Toronto [they have a contract with them] & u can just deposit it in your a/c (after landing in Canada).
If in Toronto - it gets encashed in 48hrs. Mine did. Also note that it's immaterial in which bank u opened the a/c. But if u do so in a BMO Br. here - the encashment is also on the spot. Others, 48hrs.
Regards,
Qorax