The RS-232 to ethernet is hardware. The other part is software.
For the hardware part, there are devices called serial servers or serial gateways that convert serial to ethernet. I've found that if the serial data is Modbus, it pays to buy one with the Modbus option.
They're setup with a utility provided with the product or even Telnet.
These devices are available from vendors like HMS Anybus, Digi or Lantronix and probably a dozen others.
I'll let others deal with Win CC.