This is AmBroker Formula language . in MQL4 you can not plot in PF style but you can plot it as bars/line.
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decimals= LastValue(IIf(StrRight(Name(),3) == "JPY", 100, 10000));
Box = Param("Box", 10, 1, 100, 1) /decimals;


Revers = Param("Reverse", 3, 1, 5);




//--------------------------------------
j = 0;
PFL[0] = Box * ceil(Low[0]/Box) + Box;
PFH[0] = Box * floor(High[0]/Box);
direction = 0;
//----------------------------------------

for( i = 1; i < BarCount; i++ )
{
if(direction[j] == 0)
{
if(Low[i] <= PFL[j] - Box)
{
PFL[j] = Box * ceil(Low[i]/Box);
}
else
{
if(High[i] >= PFL[j] + Revers*Box)
{
j++;
direction[j] = 1;
PFH[j] = Box * floor(High[i]/Box);
PFL[j] = PFL[j - 1] + Box;

}
}
}
else
{
if(High[i] >= PFH[j] + Box)
{
PFH[j] = Box * floor(High[i]/Box);
}
else
{
if( Low[i] <= PFH[j] - Revers * Box )
{
j++;
direction[j] = 0;
PFH[j] = PFH[j - 1] - Box;
PFL[j] = Box * ceil(Low[i]/Box);

}
}
}
}
delta = BarCount - j -1;
direction = Ref(direction, - delta);
Hi = Ref(PFH, -delta) + Box/2;
Lo = Ref(PFL, -delta)- Box/2;
Cl = IIf(direction == 1, Hi, Lo);
Op = IIf(direction == 1, Cl - Box, Cl + Box);



PlotOHLC(Op, Hi, Lo, Cl,"", ParamColor("ChartColor",colorLightGrey), stylePointAndFigure|styleNoLabel);