This code allows to fill all empty cells by something after checking that another cell is not empty.
When I use the macro ?
When I need to fill all empty cells with the same value based on another cell that is not empty.
How to create the macro ?
Read How to create, edit, hide and select a macro in an excel report
How to create the button to associate it with the macro ?
Read How to create a button and associated it to a macro in an excel report
How is the macro ?
Copy the code below and paste it into your macro. You will see my comments in green if exist so follow the help to adapt to your need.
Dim lr As Long
Dim i As Long
' change C by the column with not empty cells
lr = Range("C" & Rows.Count).End(xlUp).Row
For i = 2 To lr
' change B by the column with empty cells
If Range("B" & i).Value = "" And Range("C" & i).Value <> "" Then
Range("B" & i).Value = "unknown"