I was digging around and tried com0com, a virtual null-modem progran that creates virtual com ports and links them.
That's "com-zero-com" - com0com
If you have Microsoft Net framework 2.0 installed, then you get a nice GUI interface for setting up com0com.
Otherwise, it's the command line for you, buddy!
It worked perfectly for linking a BPQ Async port to MixW's virtual KISS TNC function.
So I get to use MixW as a KISS TNC, and it only took one real COM port for the soundcard interface PTT. - The link between MixW and BPQ is virtual.
Works great, it's free, etc... Highly recommended.
73 DE Charles, N5PVL