permanentliy set(or append) the user environment path from a .bat-

Hi,

How can I add a filepath to the existing user environment path by using a
..bat-file (or other automatick feature). I know how to do it manually by
using the Control Panel/system/advanced. I also know how to do it in the
cmd-console - however changes made in the cmd-console does not stay
permanent. So how can a make a -bat-file (or something) that I can distribute
to other users and alter their user environment path automaticially though a
program that I ask them to run?

Best regards,
kajw