wsalam,
you can request the police station to put the date exactly when you are leaving pakistan, for example you were in pakistan on march 27 and issue the certificate on the same day and you travel on 30th March, CIC will reject your app as there is 3 days gap, thats what i mean in my sentence, either you have to issue authority letter to some one to issue it while you are in KSA or you can request them put the date of issuance as the date of your leaving the country.
hope it will be clear and wish you good luck with your process.