How do I set a DOS Environment Variable within Kixstart?

EG. SET PATH=C:\winnt;c:\\winnt\system32;y:\apps\ etc.

I want the variables to remain in the user's environment throughout any dos session in Windows, and want to do this without having to make changes to each PC's autoexec.bat.

I have tried the %comspec% var within the shell command, and tried the set/setl/setm commands, but nothing seems to work.

Regards.