I don't understand how to implement this formula: IFERROR(INDEX($C$23:$C$265, MATCH(0, COUNTIF(N$23:$N23, $C$23:$C$265), 0),1),"")
I need to remove the duplicates in list C23:C265 and place the new entries in N23:N52
I've tried putting it in cell n23 and copying down but it doesn't produce...