Magic Mouse: Horizontal Scrolling under Windows XP

I'm a big Excel user, and when I saw the capability to horizontal scroll with the magic mouse under Excel for Mac - it was just something I "had to have".

Unfortunately, I work 99% of the time under Windows XP using bootcamp. There all the functions of the magic mouse work except the horizontal scoll in XL2003. (Actually I can't get the horizontal scroll to work in Chrome or Safari either)

I've updated all my bootcamp drivers to 3.1 (which supposedly addressed support issues for magic mouse) but haven't been able to get that horizontal scroll to work.

Has anybody gotten the magic mouse horizontal scroll to work in XL2003 under XP?

Any help greatly appreciated