2.1prealpha as PDC rpcclient - determining if a user is logged on

[Dave.Stevenson at durham.ac.uk]

I've been hacking a few quick and very dirty Perl scripts to do
a bit of remote NT admin (kicking off InstallShield silent installs and that kind of thing)
and a couple of things (well several actually) came up that I haven't figured would be useful.

1/ Is there a way to figure out if a user is logged in (at the screen) using
rpcclient without peeking around in the registry? ( And if possible, finding out
how long they have been logged on?)

2/ Is there a way to remotely start the schedule ( or any other) service from rpcclient?
( svcenum appears broken by the way :-(  with
   Memory allocation error: failed to expand to 1861484544 bytes
   svc_io_r_enum_svcs_status: Realloc failed
   )
Haven't looked yet to see where this is happening 
   
3/ shutdown -r   - the -r isn't obeyed faithfully it seems 
( stops me starting schedule remotely by poking registry and rebooting :-( )


4/ Solaris 2.6 hosting Samba 2.1pa - has anyone solved/worked around the
limited number of entries in /etc/group so that Domain Users enumerates
ok with more than 30ish users? - asked before but silence... so either
the answer is NO or the answer is obvious and I'm  off back to Solaris kindergarten

Any suggestions would be welcome. 

Dave