Making subsequent cells equal to the one above

Hi, so what I am looking to do is say you have an aging report with some vendors that have one invoice and some vendors have multiple invoices. So I insert 2 columns to the left of A and get my if statements going to where they are parallel to the invoice number now when I copy the formulas down, some will be what I want, some will be "0". I want to first, select only the zeros, then I want the vendor number next to every invoice that a customer has. I am using excel 2016. I did attach a sample but not sure if it uploaded.

Update; I have been able to get rid of the 0's and do F5 + ALT + S + K to select just the blank cells. Now I need to be able to put the vendor number and check number where the blanks are.

Update 2; for anyone else with this problem, I have actually found the solution.

If your customer vendor numbers contain "0"s in your if statement, replace the if false criteria to a dash "-" rather than a zero. Find and replace dashes to blank cells.

Next, F5 then Alt + E + S + K to select only the blank cells, then in the first highlighted blank cell will be white; here you would do "=" A2 for example, then hit CTRL + Enter.