I'm wondering if it it is possible to build a logon script, for Windows XP & Vista, that will detect where the user is connected to a particular network (Defined by IP schema). If they are connected to a specific network, then it will display a message such as, "Please note your will not be able to access the XYZ Network Drive, or your company email"
Why do this with batch file gyrations when you can just link GPOs to site objects? The "bonus" being that if you add addt'l subnets or move subnets around you'll never have to edit your script.
If you're looking at this being a user logon script that you want to apply only when users logon to specific computers then you'll need to look at using loopback group policy processing as well.