In most cases, you can temporarily change an environment variable by using the Windows NT set command from a Windows NT command prompt.
For example, to change the value of DSQUERY temporarily, enter this in a Command Prompt window:
set DSQUERY = new-value
Any Sybase product that you start from the current window uses new-value rather than the value specified in the Windows NT Registry. new-value is lost when you close the window or log out of Windows NT.
You cannot override the PATH environment variable using the set command.