Detect custom indicator Draw

[Ulfr11]

Hello y'all, i have a custom indicator wich i indexed some data to detect and draw an arrow, now i want a EA to detect said arrow and place orders...

{
   IndicatorBuffers(8);
      SetIndexBuffer(0,line1); //SetIndexLabel(0,"putalinea");
      SetIndexBuffer(1,line2); //SetIndexLabel(1,"putalineb");
      SetIndexBuffer(2,hist1); SetIndexStyle(2,DRAW_HISTOGRAM);
      SetIndexBuffer(3,hist2); SetIndexStyle(3,DRAW_HISTOGRAM);
      SetIndexBuffer(4,arrod); SetIndexStyle(4,DRAW_ARROW); SetIndexArrow(4,159); SetIndexLabel(4,"putaflechaa");
      SetIndexBuffer(5,arrou); SetIndexStyle(5,DRAW_ARROW); SetIndexArrow(5,159); SetIndexLabel(5,"putaflechab");
      SetIndexBuffer(6,trend);// SetIndexLabel(6,"putamierda");
      SetIndexBuffer(7,trena);// SetIndexLabel(7,"putamierdab");
         indicatorFileName = WindowExpertName();
         calculateValue    = TimeFrame=="calculateValue"; if (calculateValue) { return(0); }
         returnBars        = TimeFrame=="returnBars";     if (returnBars)     { return(0); }
         timeFrame         = stringToTimeFrame(TimeFrame);
   IndicatorShortName("indicadortrend");
   return(0);
}

wich is the best aproximation to detect the arrows at buffers 4 and 5 into a EA?, i would like to know, THANKS IN ADVACE