TOPIC: Allow registrant to return to complete fields?

Is there any way to allow a participant to come back to an existing registration to edit/complete additional fields after completed registration? I have event evaluation fields that I would like to be able to ask the participant to come back and fill in, but it's not clear to me if this is at all possible? I know my admins can go in and edit the event record itself and fill in those fields, but can I let the registrant him or herself do it?

Using our user panel, the user can come in and edit the registration record up until the event is over. They can't edit the record AFTER the event. The user panel is intended for logged in users to edit, cancel, make payments, etc... all based on what you setup as options for the event.