windows - Where do the environment variables for an elevated cmd.exe process come from?

The environment variables shown by the SET command can be notably different depending on the
privilege level of the command prompt session. Moreover, it seems that any program run with
administrative credentials by the same user can create environment variables that will persist long after that process ends, and will be set in any subsequent elevated process
launched by that user (and ONLY in those elevated processes). I have not been able to find those variables in the Environment tab shown by Process Explorer for any process associated
with the user login session. My Question is: where are those values stored, and why is
Process Explorer unable to access them (of course, since Process Explorer runs elevated by
default those variables appear in its own Environment tab)? Or did I just overlook them?