You know transfrering/distributing .bat files over the internet is illegal. So I would find a converter and convert your .bat file to a .exe file. .exe files are much easier to set as a auto-run plus they're totally legal as far as I'm concerened...
An auto-run at login is different.
You have to reun the .bat file with a code that is like,
move/copy C:\Your file.bat C:\Documents and Settings\my user (or all users)\Start Menu\Programs\Startup
Once you run this it will put your .bat in the starup folder and It *should* run on startup!
Hope this helps!