DBI, the standard perl database interface module, can be used
to work with MsSql using DBD::ODBC. If your perl script
is gonna run on something other than NT you have some
additional hoops to jump through (like getting an apropriate
ODBC driver or using DBD::Proxy).
If you are working from Linux or other GNUish/BSD ish
platforms, you can also install the Sybase libraries and
treat the M$SQL server as a Sybase machine. Handy trick
once in a while.