Or you could use mount_smbfs from FreeBSD:

mount_smbfs //user@server/share /mountpoint

(See /usr/share/examples/smbfs/dot.nsmbrc for setting up passwords and such.) Or you could use samba to download the file:

smbclient //server/share -U user%pass -c 'cd "dir"; get "file"'

Or you could use Filesys::SmbClient to access it as a perl filehandle without mounting anything. (Though you'll have to install libsmbclient first.)