Getting a fixed R-square value from linear trendline

Hello people


(Please refer the excel file)

I have to select specific data starting from 100 at X-axis till the point where R-square value is 0.99

Right now I have do it manually by first removing the initial points from 0 to 100 and then removing points backwards from 700 or so till 300 something and see when I get 0.99 as the R-square.

Is there a shortcut to do it? I have a lot of raw data and any help with save loads of my time.

Thank you in advance!


Anmol