[Wine] global wine installation

[robuntu]

Hello forum,
I am a Teacher at a German school and I want to get rid of Windows.
I successfully installed Ubuntu 10.04LTS and configured the system to
run as needed.
My Problem is the following:
I have 900 Users. If all of them use wine to start a program, every user installs his own .wine directory with all the content.
Soon I have gigabytes of redundant stuff.
Also I need to install some winetricks and I don't want to let the users do so.

With linux programmes (and with wine itself) I can install everything global with sudo.

How can I install the needed wine-components and the needed "helpers" (e.g. mdac28) global as well?

Thanks for your help
Roland