sma of daily lows on multitimeframe

[easyfying]

i use 60 min time frame and add daily timeframe to my strategy to filter out trades.
how do i calculate the 4 day sma of the daily LOWS(not close )from daily timeframe.
i was able to get the 4 day sma of close as follows

protected override void Initialize()
{
Add(PeriodType.Day, 1);
protected override void OnBarUpdate()
{
if (BarsInProgress == 0)
if(SMA(BarsArray[1], 4)[0] < Close[0] )

[NinjaTrader_Austin]

easyfying, you can use the Lows[1] data series to get the lows of the secondary series (with bar index = 1):

if (SMA(Lows[1], 4)[0] < ...)