How to edit and batch export native codec?

I am working with FCP10 and cannot find a way to export the native codec as the software only allows to export in Apple Prores. Mpegstream doesn't run smoothly on my new MacBook Pro. Any suggestions for a work flow? Thank you, Michael

What is the native codec? You could download the free version of Blackmagic's DaVinci Resolve, load your ProRes file into it and export in the native codec... assuming Resolve supports it. That's a lot of transcoding, though. Why not just upload as ProRes?