Getting smaller bars values than actual timeframe

 
Hi there,

I am coding a volatility indicator at the moment.

I will watch my indicator on the H1 chart BUT... I need all M1 open/close values within that H1 bar being processed by start().

So, for each start() on H1 chart, I need to grab 120 M1 values (60 Open + 60 Close).

How can I grab those data? I browsed the doc with no success..
 

double opens[60], closes[60];

for(i = 0; i < 60; i++){

opens[i] = iOpen(symbol_name, PERIOD_M1, i);

closes[i] = iClose(symbol_name, PERIOD_M1, i);

}

 
Great thank you !!