EA Code for Highest High and Lowest Low

Hi,

I just need a code for my EA to find the highest high and lowest low excluding 2nd, 3rd, 4th bars from the current bar. 

It is like define the top range and low range for X number of bars (LookBackBars) excluding bars 2nd, 3rd, 4th. 

So far I have this which include 2nd, 3rd, 4th bars.

int high_bar = iHighest(Symbol(), Period(), MODE_HIGH, LookBackBars, 0);

double high = iHigh(Symbol(), Period(), high_bar );

int low_bar = iLowest(Symbol(), Period(), MODE_LOW, LookBackBars, 0);

use the bar as an index to get the low value

double low = iLow(Symbol(), Period(), low_bar );