Here is a quick description of my problem:

I am trying to connect my Arduino programmable board with Microsoft Flight Simulator (3D) using vb.net app to communicate between them.

By rotating the encoder on the Arduino, board sends a signal via COM (USB) port to the computer. My vb.net application reads the port and needs to send a keystroke to Flight Simulator.
I have already tried using the "send key" function:

Code:
SetForegroundWindow(FsimHandle)
                    SendKeys.SendWait("h")
I do get output in Notepad and similar programs, but my Flight Simulator (ran in windowed mode) simply does not register it. If I try using the MS On-screen keyboard, however, I do get the desired effect. Also pressing the key on the real keyboard works :

The problem is that Flight Simulator only accepts KEY inputs, and I just don't know how to implement this using vb.net.

Kindest regards,

Nikola