Maya startup questions

Hi
I am having a little trouble modifying where user prefernces are read from. I cant use maya_app_dir as I need that to connect up all the pipeline startup data (load shelves , plugins centrally ect)
the plan is to centralise everyones  user prefs so they can jump on any machine in the studio and they will automatically load.
does anyone know of another way to set where maya reads and writes the user prefs from?

What operating system? (they work differently with mac version being completely retarded in this case)

I mean its much easier and productive to actually have users global settings reloacated by the os so the profiles roam. At the university where i work all my profiles roam across ALL systems so without hacking my windows and linux machines are in sync for ANY application. Incidentally with one easy change in linux (by symlinking the windows maya dir to the unix home) even my windows and linux machines are in sync easily without the admins doing anything. Presumably the same trick that works on linux would work on the mac workstations but theres no macs close to me that have maya licenses. The good thing is that even things like after effects, photoshop, illustrator, indeisgn all my CAD applications, mathematica, etc etc all are the same no matter where i go (that means i have about 20 000 computers that I could use with no modification to maya, only the apps installed change by computer and anything i have on local scratch off course).

Anyway on windows and linux you can just change the USERPROFILE and HOME variable in the shortcut icons launch, if you must but much better to roam the entire user profile space of the os itself. On mac im sure you could use symlinks but otherwise its a  bit retarded in maya configuration sense. But again all OSes can roam. So roam them instead.

we are using several flavours of windows - you would have to  be very wealthy to run a studio with macs.
the roaming profile thing isnt what I am looking for.  the purpose of wanting to centralise user prefs is so we can replace thier machine and maya will work the way that they need it to on thier new machine with no fuss or fiddling. we dont care about what else is on thier machine as everything work related lives on the servers.