Hi there. I think what's required is to have the work contract in your hand and then yuo'll need to go outside of
Spain to a consulate (Portugal, for example) and have it made into a Visa and then go back into Spain with it officially. Usually the labour minister in Spain has to sign it to make sure it's legal and with his signature on a document, you'll get your Visa. For the exact cost, contact the Canadian Consulate in a Spanish city to know exactly. Good luck! Emily