Figured this out after going through another thread!
Go to http://www.jobbank.gc.ca/content_pieces-eng.do?cid=6843
After filling up details, where it asks for your SIN, click on 'I have a Express Entry number' (something similar in the centre of the page)
Your Application Number is in the first column in MyCIC page (something like 'E000545654')
Your job seeker code is the last 4 digits of your passport
Continue with the process... fill up your details & logout.
Now when you log in to MyCIC, you would have a message & your profile will look like this.
Where is this application? Details
Application/profile status Open
Province/Territory Nomination No nomination at this time
Job Bank Registration Accepted
Review of Minimum Entry Criteria Met
ITA Status No invitation at this time
You are in the pool now. Congratulations Smiley