Set Display Settings to EXTEND mode in Windows 7 using C++

ExtendedDisplay.cpp

public void main(int argc, char const *argv[])
{
	// To identify the current configuration:

	UINT32 PathArraySize = 0;
	UINT32 ModeArraySize = 0;
	DISPLAYCONFIG_PATH_INFO* PathArray;
	DISPLAYCONFIG_MODE_INFO* ModeArray;
	DISPLAYCONFIG_TOPOLOGY_ID CurrentTopology;

	GetDisplayConfigBufferSizes(QDC_ALL_PATHS, &PathArraySize, &ModeArraySize);

	PathArray =   (DISPLAYCONFIG_PATH_INFO*)malloc(PathArraySize * sizeof(DISPLAYCONFIG_PATH_INFO));
	memset(PathArray, 0, PathArraySize * sizeof(DISPLAYCONFIG_PATH_INFO));

	ModeArray =   (DISPLAYCONFIG_MODE_INFO*)malloc(ModeArraySize * sizeof(DISPLAYCONFIG_MODE_INFO));
	memset(ModeArray, 0, ModeArraySize * sizeof(DISPLAYCONFIG_MODE_INFO));

	LONG ret = QueryDisplayConfig(QDC_DATABASE_CURRENT,&PathArraySize, PathArray, &ModeArraySize, ModeArray, &CurrentTopology);
	// Above CurrentTopology variable will aquire the current display setting (ie Extend, Duplicate etc)

	free(PathArray);
	free(ModeArray);


	// To set the required display setting (Extend, Duplicate etc):

	SetDisplayConfig(0,NULL,0,NULL,SDC_TOPOLOGY_EXTEND|SDC_APPLY);
	// To set to Duplicate:
	// SetDisplayConfig(0,NULL,0,NULL,SDC_TOPOLOGY_CLONE|SDC_APPLY);

	return 0;
}

Is there a way to select the display I want to mirror into? "assuming I have more than 1 external display connected".
Thanks.