Am I right in assuming that This cannot be done?
It can be done, and many before you have done it. You need to install Samba server on your linux machine and configure it. Once done, you can share files, directorys and printers.
Have a look for samba in the tutorials, networking section for some guidance on the How-to part. Maks a simple configuration first, get it working, then you can make it as complex as you need to.