Good afternoon,

Im looking for a formula that will either count unique values in a column or just identify what is duplicated but only show the duplicate for the 2nd value and not the first.

Im using a simple Sumproduct 
=Sumproduct($A$1:$A$100="1120")*($F$1:$F$100))
this will count everything in column F if column A has the number 1120 in it but in column F there is duplicate entries so i want to only count the distinct values in column F.

Or use a spare column to look at column F and Flag the account as duplicated so i can then add this criteria into my sumproduct but i only want to flag the 2nd value as duplicate and not the first entrie otherwise when i add the criteria to the sumproduct im going to disregard anything that is a duplicate which i dont want to do, i just want to count the unique entries.

Either way i need some help, can anyone assist me on this.

Thanks

DJ