Unfortunately, this is not possible (cannot boot multiple OS's from one card in a MP).
You'd need to run a separate disk for Windows off of the system's SATA ports (ICH). You can even do this for both OS X and Windows, and just keep the data on the array. Another option would be to run a separate OS X boot disk or array off of the card (totally separate from the data array = do not share the disks via partitions).
Or you can use a single disk for both OS's (use BC to share it).