problem with unicode conversion

[Jeronimo]

Hi i am trying to do one program to trigger key's in one game. But my problem is here when i try to convert my key info:

int result = ToUnicodeEx(pKeyboardStruct->vkCode, pKeyboardStruct->scanCode, keyboard_state, buffer,4,0,keyboard_layout);

Here i put the steps to get unicode text:

BYTE keyboard_state[256];
GetKeyboardState(keyboard_state);
wchar_t buffer[5];
HKL keyboard_layout = GetKeyboardLayout(0);
    int result = ToUnicodeEx(pKeyboardStruct->vkCode, pKeyboardStruct->scanCode, keyboard_state, buffer,4,0,keyboard_layout);

But for some strange reason works only with key modificators:

UpdateKeyState(keyboard_state, VK_CONTROL);

So probably for this happen.
For some reason i can't get the unicode text to use in my game.