首先根據程序名獲取到程序的ID（這裡只是測試，所以只需要得到其中一個ID就行了）GetPidByProcessName
然後根據程序ID獲取視窗控制代碼 GetHwndByPid
最後將視窗前端顯示並置頂 ShowForeGround

//根據程序名獲取程序ID
DWORD GetPidByProcessName(TCHAR *pProcess) 
{ 
    HANDLE hSnapshot; 
    PROCESSENTRY32 lppe; 
    //建立系統快照 
    hSnapshot = ::CreateToolhelp32Snapshot
 
(TH32CS_SNAPPROCESS, NULL); //#include<Tlhelp32.h>

    if (hSnapshot == NULL) 
        return 0; 

    //初始化 lppe 的大小 
    lppe.dwSize = sizeof(lppe); 

    //查詢第一個程序 
    if (!::Process32First(hSnapshot, &lppe))
        return false; 
    do 
    { 
        if(StrCmp(lppe.szExeFile, pProcess) ==
 
 0)
        { 
            return lppe.th32ProcessID;
        }   
    } 
    while (::Process32Next(hSnapshot, &lppe)); //查詢下一個程序  

    return 1;
}

//根據程序ID獲取視窗ID
HWND GetHwndByPid(DWORD dwProcessID)
{
    //返回Z序頂部的視窗控制代碼
    HWND hWnd = ::GetTopWindow(0);

    while ( hWnd )
    {
        DWORD pid =
 
 0;
        //根據視窗控制代碼獲取程序ID
        DWORD dwTheardId = ::GetWindowThreadProcessId( hWnd,&pid);

        if (dwTheardId != 0)
        {
            if ( pid == dwProcessID )
            {
                return hWnd;
            }
        }
        //返回z序中的前一個或後一個視窗的控制代碼
        hWnd = ::GetNextWindow(hWnd , GW_HWNDNEXT);

    }
    return hWnd;
}

//前端顯示並置頂視窗
void ShowForeGround(HWND hWnd)
{

    if (hWnd)
    {
        //顯示視窗
        ::ShowWindow(hWnd, SW_NORMAL);

        //前端顯示
        ::SetForegroundWindow(hWnd);

        //視窗置頂
        ::SetWindowPos(hWnd,HWND_TOPMOST,0,0,0,0,SWP_NOMOVE|SWP_NOSIZE);
    }
    else
    {
        ::MessageBox(NULL, _T("未找到視窗"), _T("提示"),MB_OK);
    }
}

void CMFCApplication1Dlg::OnBnClickedMfcbutton1()
{
    DWORD dwPid = GetPidByProcessName(_T("notepad.exe"));
    HWND hWnd = GetHwndByPid(dwPid);
    ShowForeGround(hWnd);
    //傳送按鍵F1訊息，等同F1被按下
    ::PostMessage(m_hwnd, WM_KEYDOWN, VK_F1, 0);
    ::PostMessage(m_hwnd, WM_KEYUP, VK_F1, 0);
}