HWND hWnd = ::FindWindow(NULL, L"XXXXXXX");

	if (hWnd != NULL)

	{

		DWORD dwReadBytes;

		unsigned char *lpbuffer = (unsigned char *)malloc(10 * 1024 * 1024);;

		USES_CONVERSION;

		LPCSTR path = (LPCSTR)T2A(m_strDescPath); //m_strDescPath为一edit组件的成员变量

		HFILE splhandle = _lopen(path, 0);

		dwReadBytes = _lread(splhandle, lpbuffer, 10 * 1024 * 1024);

		COPYDATASTRUCT cpd; /*给COPYDATASTRUCT结构赋值*/

							//cpd.dwData = 1;                                                                                                         //标志发送字符串

							//cpd.cbData = strlen("字符串")+1;

							//cpd.lpData = "字符串";

							//::SendMessage(hWnd,WM_COPYDATA,NULL,(LPARAM)&cpd);//发送！

		cpd.dwData = 1; //标志发送CString类型

		cpd.cbData = dwReadBytes;

		cpd.lpData = lpbuffer;

		::SendMessage(hWnd, WM_COPYDATA, NULL, (LPARAM)&cpd); //发送！

	}