Hi Dominique,
I've never modified sth. around the workflow process so I can only speek theoretically and give you a few hints

.
My guess would be that you're storing the additional info during registration with custom attributes (expando) for the type user, right? If so the next step would be to identify the jsp displaying the data for the review task. Maybe it's located somewhere in one of the "
html \ portlet \ workflow_*" folders. Next you should create a hook and override the jsp. You can access custom attributes by using "
userObj.getExpandoBridge().getAttribute("my-additional-attribute")". If I remember rigth there is also a taglib for displaying custom attributes.
It's not much of a solution but I hope you can at least use it to find one

.
Greets Oli