Emulating keyboard with Leonardo

Hello,
I am a beginner with Arduino. I have bought Arduino Leonardo and Keyboard.
The problem are ctrl keys, I would like to have for example ctrl+c on one key.
It works for example in notepad and chrome, but it doesnt work in microsoft word or autodesk inventor.
Why is it like that?

Here is part of my code:

if ((sensorValue>220)&&(sensorValue<250))

{
Keyboard.press(KEY_LEFT_CTRL);
Keyboard.press('C');
Keyboard.releaseAll();
delay(300);
lcd.print("COPY");
delay(1000);
lcd.clear();
}

Thank you
Vito

Try with 'c' instead of 'C' to get Ctrl-C and not Ctrl-Shift-C.

Solved.
Thank You very much!