If you have trouble with Windows signed drivers, use version 188.8.131.52
This could be more difficult to use, but that would be difficult to do. "com2tcp" was not in the Windows download and after spending more time than it would have cost to purchase a commercial product, I finally located the file. Then I had to use two different windows and two different virtual pairs of devices to create two virtual serial ports. Finally, my application, which is based on RXTXcomm, doesn't recognize "CNCA0" as a device, so I had to use "\\.\CNCA0". I'm sure there is an easier way (I hope) to do all this, but I'm not going to stick around to figure it out. Sorry for the harsh review -- com0com is not ready for prime time.
I downloaded several programs for emulation virtual null modems, also com0com. But the best for me is Null Modem Emulator by Eltima - this software is fully baked.