You should be able to simply use something like:
mount -t smbfs -o username=MyAccount //Server/share /mnt/dir
Where MyAccount is a account with rights for the share (unless you use guest access), //Server/share is the UNC path and /mnt/dir is the local mountpoint.
If memory serves of course.. I'm still a bit of a newbie...
[edit]Whoopss... Slow typin'![/edit]