I have a series of 15 cells that return letter values depending on an IF statement. I need a data validation to be created depending on the values returned in these 15 cells. Here is a preview of the full formula I need to fit into my data validation list.

=IF($F$68="AA",INDIRECT($F$68),IF($F$69="A",INDIRECT($F$69),IF($F$70="B",INDIRECT($F$70),IF($F$71="D",INDIRECT($F$71),IF($F$72="E",INDIRECT($F$72),IF($F$73="F",INDIRECT($F$73),IF($F$74="G",INDIRECT($F$74),IF($F$75="AB",INDIRECT($F$75), IF($F$76="I",INDIRECT($F$76), IF($F$77="J",INDIRECT($F$77), IF($F$78="AC",INDIRECT($F$78), IF($F$79="L",INDIRECT($F$79), IF($F$80="AG",INDIRECT($F$80), IF($F$81="AI",INDIRECT($F$81), IF($F$82="AK",INDIRECT($F$82),$I$73)))))))))))))))

If it helps, I have also combined those 15 cells into 3 cells based on a longer formula which each cell is capable of returning 5 different letter values. Thinking in a different way, maybe a data validation formula returning values based on the results of those three cells.

Please let me know if it is possible to shrink my above formula into one that would work for a data validation list.

Thanks!