Yeah, I have had the same conversation with the paypal support reps, and have seen numerous other posts in support forums where they also had the support reps say it is possible, but then on implementation it doesn't work.
i have yet to find a way to pass those details that actually works and have scoured the documentation with no luck.
in eCart, the checkout wizard can be configured to store the order information to the database. it is fairly easy from there to create an order history page to get the information from the database.
see the following tutorial: