Using Variables in Quiz Results Messages

Review Area is only used for skipped questions on quiz slides, and for the score slide to show the final feedback messages. I suppose you talk about the last one? It cannot be done with the default messages. Use a multistate object with both messages or a group of two individual messages. Delete the default Review message. Use the On Enter event of the score slide to create a conditional advanced action, using the system variable cpQuizInfoPassFail. Here is an example for the Show/Hide workflow (I used two shapes as feedback messages):

Nice idea, but I don't think you can add User Variables into those places in Quiz Settings.

In any case, the Review Area for individual quiz questions is not really used nowadays in Captivate because it was originally used to show the correct answers when the learner was in Review Quiz mode.  Many versions ago now Captivate introduced a different method of showing the correct and incorrect answers using small checkmark and cross icons.

If you are talking about customising the content of the Review Area on the Quiz Results slide, a better method to do that is to add a Shape with multiple object states and show the relevant states depending on the user score via a Conditional Action triggered on entering the Quiz Result slide.