In my published app, I wish to give the user a button that will open the iTunes
page for the app, and navigate to the Add a Review
section for the app.
Is it possible to create a url to do this?
Yes, that's possible. Read this article. In short, your URL will look like this:
itms-apps://ax.itunes.apple.com/WebObjects/MZStore.woa/wa/viewContentsUserReviews?type=Purple+Software&id=337064413
You'll have to replace the id with your App's id.