Are you trying to change the INDEX/MATCH formula in the link? The formula in the link is for 8 rows & 2 columns (not sure where you get 8 columns).
We need more info. based on your worksheet.
1-What column has the data you want to return (it was A in the link)
2-What cell has the criteria you are looking up (it was E1 in the link)
3-What column has the data for the criteria (it was B in the link)