Hope this is still relevant...
Just have a look at com2com, tcp2com and hub4usb. They are all on SourceForge, just start from
http://com0com.sourceforge.net/[
^].
It is a Null-modem emulator, COM port to TCP redirector, and HUB for communications.
Using hub4com you can redirect incoming messages from your COM ports to multiple virtual COM ports quit easily. This way you can have the best of all three solutions mentioned.
Happy coding ;-)