How to make ?

 
Hello,
Somebody could it help me please?
I seek how to modify the indicator "Average True Range" of Metatrader 4 so that it indicates the difference between the open and the close and not between highest and low.
I thank you for your answers.
Alexandre



How to make ????????



//+------------------------------------------------------------------+
//| ATR.mq4 |
//| Copyright © 2005, MetaQuotes Software Corp. |
//| https://www.metaquotes.net/ |
//+------------------------------------------------------------------+
#property copyright "Copyright © 2005, MetaQuotes Software Corp."
#property link "https://www.metaquotes.net/

#property indicator_separate_window
#property indicator_buffers 1
#property indicator_color1 DodgerBlue
//---- input parameters
extern int AtrPeriod=14;
//---- buffers
double AtrBuffer[];
double TempBuffer[];
//+------------------------------------------------------------------+
//| Custom indicator initialization function |
//+------------------------------------------------------------------+
int init()
{
string short_name;
//---- 1 additional buffer used for counting.
IndicatorBuffers(2);
//---- indicator line
SetIndexStyle(0,DRAW_LINE);
SetIndexBuffer(0,AtrBuffer);
SetIndexBuffer(1,TempBuffer);
//---- name for DataWindow and indicator subwindow label
short_name="ATR("+AtrPeriod+")";
IndicatorShortName(short_name);
SetIndexLabel(0,short_name);
//----
SetIndexDrawBegin(0,AtrPeriod);
//----
return(0);
}
//+------------------------------------------------------------------+
//| Average True Range |
//+------------------------------------------------------------------+
int start()
{
int i,counted_bars=IndicatorCounted();
//----
if(Bars<=AtrPeriod) return(0);
//---- initial zero
if(counted_bars<1)
for(i=1;i<=AtrPeriod;i++) AtrBuffer[Bars-i]=0.0;
//----
i=Bars-counted_bars-1;
while(i>=0)
{
double high=High[i];
double low =Low[i];
if(i==Bars-1) TempBuffer[i]=high-low;
else
{
double prevclose=Close[i+1];
TempBuffer[i]=MathMax(high,prevclose)-MathMin(low,prevclose);
}
i--;
}
//----
if(counted_bars>0) counted_bars--;
int limit=Bars-counted_bars;
for(i=0; i<limit; i++)
AtrBuffer[i]=iMAOnArray(TempBuffer,Bars,AtrPeriod,0,MODE_SMA,i);
//----
return(0);
}
//+------------------------------------------------------------------+
Reason: