Requirement for formfiller to view/edit own submission only at later date

This is a great module which does all I need apart from the ability for the form filler to view/edit own submission, but not others, either via a password field within the form or on subsequent login, if login is required to access/submit the form). Is this a feature that can easily be added, or do you have any advice as to how I might accomplish this.
Any help/suggestions would be much appreciated asap, as I need to utilise this within the next few days.