Just consider the following in your Logon UDC...
SETVAR SysVS "MPEXL_SYSTEM_VOLUME_SET"
and life can become someting like...
discfree "e,,!SysVS"
altgroup xyz ;homevs=!SysVS
store ;;directory;onvs=!SysVS,Users,Dumps
volutil "altervol !SysVS:member1 95 95"
report ;onvs=!SysVS
...
Cheers, Lars.
(yes, I know, this is only 90% of a $SYS shortcut ;-)