I'm not a huge expert on Windows NT, but couldn't you run the 'net' command from inside a perl script and simply process the output to get the desired result? Find some detailed info on the 'net' command: here.

my @net_info = `net config`;

# @net_info should contain lines of output
# produced by the 'net config' command.
# I hope they should contain work group info?

while (@net_info) {
  # parse the line here...

  print "$_\n";
}
[download]

_____________________

# Under Construction
[download]