Set parent env with csh script

[Guy Harris]

 >> Is it possible for a subshell to change the calling shell's 
 >> environment?  How?
 >
 >You can use getenv(3C) from a C program to return the address of an
 >environment variable of the form name=value.  You can modify what is
 >stored at that location, but not with impunity.

This won't do anything about the copy of that environment variable (if
any) in the *parent* process of the process in which it's done, which is
what the guy wanted.