i.e.

Set WshShell = WScript.CreateObject("WScript.Shell")
Set WshSysEnv = WshShell.Environment("PROCESS")

WScript.Echo WshSysEnv("HOMEPATH") = "J:\JOHN\MYSTUFF"

WScript.Echo WshSysEnv("HOMEPATH")

the third line displays 0, the last line displays my regular path, not what I tried to change it to. Maybe I'm going about it wrong, but I took it to mean that it was read only.
John