Tricky one here (I think):

I have a drop down list of Labor Periods on a cover sheet.

On a separate data sheet I have:

Period 1 Period 2 ...
Units Cost Hours Units Costs Hours

The oldest Labor Period is the farthest to the right.

I need a formula that will find the Labor Period selected from a drop down
(DV) and sum the values to the right of that Labor Period.

So if Labor Period 5 is selected, I want to add up the hours for Labor
Periods 5,4,3,2,1.

Any help would be lovely.

Beric