Hi all,
Ressurecting this old thread because I find adding this information relevant and useful.
I have returned after over five years to fly DCS, set up my sim pit, new Windows 10 installation and noticed I can't get this to work.
What I have found out during t/s process is that TrackIR 5.4.2 drivers suffer regression compared to 5.4.1 drivers I have used back in 2016. Uninstalling 5.4.2 and installing 5.4.1 driver software enabled again use of F14 through F24 keyboard functions via AutoHotKey script reading joystick buttons.
I hope this helps someone!
Happy flying