Kix knows the SET, SETL and SETM commands. With these commands you can set user as well as machine environment variables, check the manual which you can download from this site.

The %comspec% /c ; %comspec% is a variable which is used for the command line. (check your environment vars !) /c is a command line switch used to start the program and to return when it has finished.
(use command.exe /? on W9x to see them all)

Hope it helped..

Bert.