JPA is for OO programs which need a OO view of persistence storage.
if you want exact resultSet then JPA is not much a good choice for you.
for example if you want feed this result into a report or OLAP software, which user creates a SQL to run you may prefer to bypass JPA
please refer to "Fast Lane Reader" pattern
in such a cases create a "Session Facade" for this set of queries  that runs all "Stored Procedures" and "Native Queries" with special set set of columns in result set.