I have table1 that has the header row of year and the A column as the project name, and in each cell is a factor.
I am using the formula =INDEX(D14:130, MATCH(M17, C14:C30,0), MATCH(P13, D13:I13,0)) this gets me the value of the factor and works great.
What I need to do is sum the factors from this cell going back x number of cells, where x is determined by a different cell (say A2). The catch is that there sometime wont be enough cells to go back that far, because my Table1 only starts from 2005, but A2 might be 25, so it would try to go back 25 years.
Thanks,