Howard W. answered 01/22/20
Network Security Engineer - CCIE R/S #54123, GDSA, GCIA
Hello,
Unfortunately, there isn't much configuration support for the SG300 platform. If you could replace this device with an IOS based switch such as 3560/3850 you could enable the private vlans feature. This feature will could lock down the PC to ONLY configure with the network file share.
-Information about Private Vlan configurations
https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3560/software/release/12-2_52_se/configuration/guide/3560scg/swpvlan.html