Index Indicator (Indicator of an Indicator)

 

Hi guys, I have seen this indicator: https://www.mql5.com/en/code/mt4


and I want to have an index indicator that computes and plots the graph of the index of the above indicator?


the formula is this:


[TODAY'S READING of above indicator - LOWEST READING of above indicator(say in the last 20days)]
------------------------------------------------------------------------------------------------------------------------------------------------- X 100
[HIGHEST READING of above indicator(say in the last 20days) - LOWEST READING of above indicator(say in the last 20days)]

variable: last X days

any help is appreciated because i am not a programmer.