There are ways your Network administrator should be able to protect the drawings, all without the workstation application (ALibre et al) from needing to know about it.
Limit "Save" rights to certain locations only, the main file server for instance.
Have no saving devices like USB ports or CD-writers on the workstation machines. Or disable them at the operating system level if they have them and cannot be removed.
Encrypt the files on "Save," decrypt on "Read" using a key only known to a select few. That encrypt/decrypt can be incorporated into the network transfer protocol so that it happens automatically and transparently to the workstation user.
Many more options. You need to find a good local person to set this up if it is beyond the current network Admin's abilities.