well, first of all, you would have to do:
"c:\windows\explorer.exe" /n /e c:
-or just:
"c:\windows\explorer.exe" c:
Switches need to be outside of quotes, otherwise it's actually trying to start the file named "explorer.exe /n /e c:" located in c:\windows. However, you can't put that in as an evar (evar's can't contain switches, only the actual program path). Where are you trying to use this, a popup, shortcut, label, or something else?