[otrs] OTRS 2.2.5 Using Autologin?

Hello, I am using OTRS 2.2.5 on a Linux Computer running Apache 2.2.6. Actually I am authenticating my users against LDAP (Windows 2003 AD Domain). This is working quite well. Now I am looking for an auto login. Is there a possibility, to use the logged in user on a computer to auto login into otrs? I only found a very short description in the manual. But when I use AuthType Basic in apache, the apache will show a login window. Is there a possibility to login without this windows? (on windows based apache web servers I found a module called SSPI, but this is only working with Win32) Any help is appreciated Achim