Changing Wins Addresses Programatically, How?

I need to change the network config on a about 1000 laptops all mobile because we were on a public IP address, sceme and not we are going to a private to release a few thousand IP addresses back out to the internet.

My Problem is I have about 1000 mobile users out there that VPN in, now yes they are all using DHCP for what ever ISP they use, but they need to have the wins servers specified.

Anyone know how to programatically change this info on a computer, I looked for it in the registry but couldn't find it anywhere. I am look for something simple that I can send out to about 1000 people in a email maybe or I can put it on a web server to download and then but all I want the end user to do is doubleclick on a exe or a script file and they are done.

Also as far as operating system, they will be from 95 to 2000. No XP, at least as far as I know there is no XP, if there is, then they did it and it is not supported by us so Anyone got any ideas