Keybd_Event为什么在游戏中模拟按键失效了？？求解！

前因：这段时间小弟玩《三国群英传三》打到三国归魏。因为难度太高，所以在网下查了密技。可是每次要敲击一串字符，故想写一个类拟于按键精灵的东西简化输入。例如，开启游戏Debug-后输入ods3on。加钱-输入money99999。我想做成按F1模拟ods3on,F2模拟money99999.
思路：做一个全局键盘勾子。当在游戏中勾到F1时，用Keybd_Event模拟键盘按下ods3on。当勾到F2时，用用Keybd_Event模拟键盘按下money99999.
问题：完成代码后，在记事本，IE地址栏都可以成功实现按下F1显示ods3on,接下F2显示money99999。可在《三国群英传三》游戏中使用无效。
相关代码：
{sg.dll}
library sg;

uses
SysUtils,
Classes,
WinTypes,
WinProcs,
Messages;

var
IsHooked: Boolean;
HookHandle: HHook;

function HookProc(nCode: integer; wParam: WPARAM; lParam: LPARAM): LRESULT; stdcall;
begin
if (nCode > -1) then
begin
if (wParam = VK_F1) then
begin
if ((lParam shr 31) =1) then
begin
Keybd_Event(Ord('O'), MapVirtualKey(Ord('O'),0), 0,0);
Keybd_Event(Ord('O'), MapVirtualKey(Ord('O'),0), KEYEVENTF_KEYUP,0);
Keybd_Event(Ord('D'), MapVirtualKey(Ord('D'),0), 0,0);
Keybd_Event(Ord('D'), MapVirtualKey(Ord('D'),0), KEYEVENTF_KEYUP,0);
Keybd_Event(Ord('S'), MapVirtualKey(Ord('S'),0), 0,0);
Keybd_Event(Ord('S'), MapVirtualKey(Ord('S'),0), KEYEVENTF_KEYUP,0);
Keybd_Event(Ord('3'), MapVirtualKey(Ord('3'),0), 0,0);
Keybd_Event(Ord('3'), MapVirtualKey(Ord('3'),0), KEYEVENTF_KEYUP,0);
Keybd_Event(Ord('O'), MapVirtualKey(Ord('O'),0), 0,0);
Keybd_Event(Ord('O'), MapVirtualKey(Ord('O'),0), KEYEVENTF_KEYUP,0);
Keybd_Event(Ord('N'), MapVirtualKey(Ord('N'),0), 0,0);
Keybd_Event(Ord('N'), MapVirtualKey(Ord('N'),0), KEYEVENTF_KEYUP,0);
//MessageBeep(0);
end;
Result := 1;
end//打开密技
else if (wParam = VK_F2) then
begin
if ((lParam shr 31) =1) then
begin
Keybd_Event(Ord('M'), MapVirtualKey(Ord('M'),0), 0,0);
Keybd_Event(Ord('M'), MapVirtualKey(Ord('M'),0), KEYEVENTF_KEYUP,0);
Keybd_Event(Ord('O'), MapVirtualKey(Ord('O'),0), 0,0);
Keybd_Event(Ord('O'), MapVirtualKey(Ord('O'),0), KEYEVENTF_KEYUP,0);
Keybd_Event(Ord('N'), MapVirtualKey(Ord('N'),0), 0,0);
Keybd_Event(Ord('N'), MapVirtualKey(Ord('N'),0), KEYEVENTF_KEYUP,0);
Keybd_Event(Ord('E'), MapVirtualKey(Ord('E'),0), 0,0);
Keybd_Event(Ord('E'), MapVirtualKey(Ord('E'),0), KEYEVENTF_KEYUP,0);
Keybd_Event(Ord('Y'), MapVirtualKey(Ord('Y'),0), 0,0);
Keybd_Event(Ord('Y'), MapVirtualKey(Ord('Y'),0), KEYEVENTF_KEYUP,0);
Keybd_Event(Ord('9'), MapVirtualKey(Ord('9'),0), 0,0);
Keybd_Event(Ord('9'), MapVirtualKey(Ord('9'),0), KEYEVENTF_KEYUP,0);
Keybd_Event(Ord('9'), MapVirtualKey(Ord('9'),0), 0,0);
Keybd_Event(Ord('9'), MapVirtualKey(Ord('9'),0), KEYEVENTF_KEYUP,0);
Keybd_Event(Ord('9'), MapVirtualKey(Ord('9'),0), 0,0);
Keybd_Event(Ord('9'), MapVirtualKey(Ord('9'),0), KEYEVENTF_KEYUP,0);
Keybd_Event(Ord('9'), MapVirtualKey(Ord('9'),0), 0,0);
Keybd_Event(Ord('9'), MapVirtualKey(Ord('9'),0), KEYEVENTF_KEYUP,0);
Keybd_Event(Ord('9'), MapVirtualKey(Ord('9'),0), 0,0);
Keybd_Event(Ord('9'), MapVirtualKey(Ord('9'),0), KEYEVENTF_KEYUP,0);
//MessageBeep(0);
end;
Result := 1;
end//每城钱财加99999
else
Result := 0;
end
else
Result := CallNextHookEx(HookHandle, nCode, wParam, lParam);
end;

function SetHook: Boolean; stdcall;
begin
Result := False;
if IsHooked then
Exit;
HookHandle := SetWindowsHookEx(WH_KEYBOARD, HookProc, HInstance, 0);
Result := HookHandle <> 0;
end;

function RemoveHook: Boolean; stdcall;
begin
Result := False;
if (not IsHooked) and (HookHandle <>0) then
Result := UnHookWindowsHookEx(HookHandle);
IsHooked := False;
end;

exports
SetHook name 'SetHook',
RemoveHook name 'RemoveHook',
HookProc name 'HookProc';

begin
IsHooked := False;
end.

{sanguo3.exe}
unit sanguo3
...
...
function SetHook; external 'sg.dll' name 'SetHook';
function RemoveHook; external 'sg.dll' name 'RemoveHook';


procedure TForm1.Button1Click(Sender: TObject);
begin
if SetHook then
Caption := '三国密技-启动'
else Caption := '三国密技-启动失败'
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
if RemoveHook then
Caption := '三国密技-关闭'
else Caption := '三国密技-关闭失败'
end;
...
...