Comparing values between columns only when there are values in bot

[Guest]

I am trying to run a YTD sales program indexing TY actual weekly sales
against TY Plan sales. The first worksheet shows current year's actual sales
as they update weekly. The second worksheet has the Sales Plan by week for
the entire year. My third worksheet is a simple YTD indexing form to track
YTD sales against YTD Plan. How do I have a cell formatted to only accept
the values in "column B" if there is a corresponding value in "column A"?
Example: Sales TY in weeks 1-3 vs Plan sales Weeks 1-3; next week 1-4 vs
Plan 1-4, etc.

 

[Otto Moehrbach]

I don't follow everything you are trying to do, but to answer your literal
question:
You can't format a cell to do that but you can put a formula in a cell to
pick up the Column B value unless Column A is empty. Something like:
=IF(A3="","",B3)

HTH Otto