I can't even find any advanced power schemes in xp that control spin down. There is a neat advanced battery monitor for laptops but I have forgotten what its called. It was shareware on a magazine dvd about a year ago again I can't remember the magazine but I used it to condition my aunties laptop battery.
When you get a new laptop you have supposed to fully charge and discharge the battery so many times before use to keep in tip top shape. This process is called conditioning. Different manufacturers have varied views to how many times this should be done. I always opt for about 5 times and playing a video dvd is best way to drain battery fast.
Back to your advanced power schemes:- you can set profiles such as day, night, office, train etc in this program. It has customizable features and a section where you have a bar chart type affair that you choose what happens at what time over 7 days per week. I dont know if this has hard drive spin down though but was pretty advanced. Sorry I can't help more but atleast you know there is a program out there.