Driver form UART communication Win CE

Device which I develop consist with Toradex Colibri T30 Module with Windows Compact Embedded System 8. Colibri T30 is working on self-developed evaluation board compatible with Colibri T30.
Overthere, with device is connected external keybord using UART. Keyboard is avaliable only in range of application. My question is what is a procedure to make keyboard visible in all systems function like for example cmd or text notepad.
As You can see on photo, basic test application correctly get letters from keyboard, but systems application don’t get it.

Dear @Introligator

If i understand you right what you want to do is have a proper system keyboard instead of only an application that accesses the COM port and read in the Serial Keyboard input.
What you need is a system keyboard driver. This can be a bit tricky to do if you never did any driver developments.
But there is another very easy solution to get the same result:
Extend you application that grabs the Keyboard input from COM port to generate systmem keyboard events.
Use the following function call:
See an example here:

Hope this helps