Procedure SendKey(H: HWnd; Key: Byte);
Var
 vKey, ScanCode, WParam      : WORD;
 LParam, ConvKey             : LongInt;
Begin
 ConvKey := OemKeyScan(Ord(Key));
 ScanCode := ConvKey And $000000FF Or $FF00;
 vKey := Key;
 WParam := vKey;
 LParam := LongInt(ScanCode) Shl 16;
 SendMessage(H, WM_KEYDOWN, WParam, LParam);
 SendMessage(H, WM_CHAR, WParam, LParam);
 LParam := LParam Or $C0000000;
 SendMessage(H, WM_KEYUP, WParam, LParam);
End;

begin
SendMessage(H, WM_KEYDOWN, VK_CONTROL, 0);
SendKey(H, 'P');
SendMessage(H, WM_KEYUP, VK_CONTROL, 0);
end;

begin
SendMessage(H, WM_KEYDOWN, VK_CONTROL, 0);
SendKey(H, Ord('P')); // <--------
SendMessage(H, WM_KEYUP, VK_CONTROL, 0);
end;