Any modern performance ball can be used for any style. What you're technically doing is bowling lefty. What you need to focus on, if you are going to stick with a backup style, is to have it laid out and drilled accordingly.
There are pluses and minuses to bowling that way. The big plus, if you're righthanded, is you're going to be able to play the left half of the lane, which sees less traffic.
The minuses, however, outweigh the pluses in my opinion: Potential for wrist injury, and it's harder to get revs on the ball throwing backup.
It's not impossible to do, though. I bowled a tournament against a guy that was truly a backup cranker. I don't know how he got his wrist to do what it did, but it did. And he was very good at what he did.