which Mac? what is the hard drive layout?
and you would need either Boot Camp drivers which includes an HFS serivce to access Mac, or if you want to write and have better access then the new MacDrive 9.x which is commercial and reviewed here:
There was a bug with usng 3TB Fusion drives that was suppose to be addressed and fixed in 10.8.4 and new drivers download from inside Boot Camp Assistant.
MacDrive is a much better method.