Unless you've got admin rights on the server - which would let you muck around with the server's smb.conf file (I'm assuming this is a Linux or OS X box running Samba) - there's not a lot you can do.
If this is your personal machine - I don't think you can do much with Apple's GUI interface for this, but if you're fairly brave you can always muck around with smb.conf after thoroughly reading the documentation at samba.org.