index.dat, cookies and PHP

[[icehole]]

Hey!

I am working on an intranetsystem for my highschool, and I am stuck on only one thing: automatic log-in

See, the system in our school works like this:

Everyone has a windows logon name they use when they need to access a terminal.

Now, what I need: to somehow read the username of the windows user currently logged in, into a variable in PHP and from there, just select the relevant information for just that person, since the database knows who the login belongs to.

The only solution I and a tech who works in the school thought of was:

As soon as a person logs into windows, novell places a text-file in the cookie directory of the user that looks like this:

cookie[three] 
username
161.52.158.7/intranet/ 
1536 
3001073664 
34491991 
2855879232 
29600033 
*

This cookie is valid for another 10 years, so that is not a problem, and the "username" part is replaced by novell with the current windows logon name.
One could say we are making a fake cookie, tricking windows and the site to think that we had already visited the site, so logon wouldnt be necessary (because I DONT want people to have to log on)

HOWEVER, here comes the problem. In (at least windows xp) there is a file called index.dat which keeps record of the cookies, and I think this is what is blocking everything from working.

So, does anyone have any idea to a solution or something like that?

Thanks // Peter