the backslash denotes a reference. you'll want to read perlreftut (off-site link--where's the local copy?) to get aquainted with references, and perlref for detailed information. additionally, you can read the docs for Win32::NetAdmin on CPAN.

Update: crazyinsomniac asked me to point you to How to RTFM, which might help improve your chances at finding answers on your own. i see you tried the docs first, which is good. Masem's node will help you take better advantage of them.

~Particle *accelerates*