After a lot of discussion with money changers and my bank i have come to following conclusion
1.,wire transfer from money changer is expensive as they charge atleast 3000 pkr for wire transfer but pkr to \cad conversion rate is very high,they may charge you almost 2 rs.extra for a CAD atleast
2.Open a bank account in USD as CAD account is not available in PAK BANKS,they charge USD 25 for one wire transaction and a negligible USD to CAD conversion rate,so u may open a USD account by purchasing it from open market on competitive rates,u have to keep these USD in your account for atleast 15 days otherwise bank will charge additional 35 usd on wire transfer,,,,so the best way is to open a usd account for your one family member who can send you this money as n when required by u there in canada