How to add an auto number next to formatted cells in excel

Question

So i wanted to add a number next to the formatted cells in the table like:

The rows are formatted if the the sales rep column to the C2 cell.

I want to make the list look like this where the column F has an auto number list:

Answer 1

Use:

=IF(B5=$C$2,MAX($F$4:F4)+1,"")

And copy down.