Share a Secured Folder between XP and Vista multi-boot

[spacesurfer]

I am multibooting XP and Vista. I have a folder called "My Finances" that I created in XP and my profile is the owner and no one else can access this folder (of course another can take ownership).

I would like to access this folder in Vista also without having to take ownership back and forth between XP and Vista. How do I add my XP credentials to Vista so I can access the folder in both OS's?

Thanks.