V-Flyer

Hi,
I'm travelling to JFK and back next month on a CO ticketed flight operated by Virgin Atlantic. I just wanted to know a few things that might be different between this (I've never flown a codeshare before) and flying on a VS ticket. Firstly, do I check in at the VS check-in desks? [:I]. Secondly, does anyone know what kind of price I could expect to pay to upgrade to PE from Y (booked in 'I' class). Thanks a lot!

P.S. If anyone knows anything else that might be of help, I'd appreciate it

If you're going to JFK I presume you are leaving from LHR whereupon you will check in at the VS desk as CO do not operate out of LHR except as a codeshare