AD Logins OD Home Directories…

Hello all! We have a setup in which our Xserve uses our Active Directory logons and Home Folders. We would like to change it so that when a user logs on to our Mac's they have a separate Home folder which resides on the Xserve, and when they log in to the Windows machines they have their AD Home folders which reside on the Windows servers (which obviously already exist). Is it possible, and if so would someone be kind enough to guide me through it? Thanks in advance!