Binding to a virtual joystick

I've played around a bit with FreePIE and VJoy.

So far I've successfully taken MIDI input in FreePIE, sent it to a virtual joystick, and used that in a game (IL-2 BoX).

I've also tried to set my headtracking output from OpenTrack to vJoy, and was able to check with vJoy Monitor that that works.

I then tried to use a virtual joystick as essentially an intermediate tier, where OpenTrack would send output to a virtual joystick, and FreePIE would use that virtual joystick as input.

My impression from trying that out, is, that it's not possible, that only 1 application such as OpenTrack or FreePIE can 'bind' to a particular virtual joystick.

This post is basically to check whether that's true, or whether maybe I've tried it the wrong way.