I suspect if you make a
Junction (proprietary-speak for symlink, only works with NTFS I believe) pointing to your F: drive, instead of using a Windows shortcut, you'll be able to access the F: drive through the shared folder on the C: drive. I could be wrong though, symlinks on my mounted NFS shares wind up trying to point to folders on the local system they're mounted on, there could very well be similar behaviour with Junction and Samba.
imho that's a security weakness of Windows if it lets you access unshared folders because there's a shortcut to them in a folder that actually is shared. The F: drive should be inaccessible remotely unless it is shared itself - which is what I think you should ultimately do, just share the F: drive or a folder on it.