Depending on input, lock or activate cells.

[jacktiser]

Say, I have cells A1:A5 to work with.

- If I input the letter "A" in B1, then A1:A5 should all be blank and allow for value/formula input with normal editing.
- If I input the text "NA" in B1, then A1:A5 should all be filled with "NA" and automatically be locked for editing

What would the formula be?

[arlu1201]

I dont think you can do the locking by formula, you will need a macro for this.

[jacktiser]

What would the formula be if I remove the requirement to have the cells automatocally locked?

[arlu1201]

Copy this formula in A1. Drag till A5.

=IF($B$1="A","",IF($B$1="NA","NA"))

[Irish RayRay]

You could use code like this.
If you wanna lock a cell the sheet has to be proctected first.


This Code goes into (Press ALT + F11 then Ctrl + R then select ThisWorkBook and Paste it in there)
if you want you could have a if statment to check your on the right sheet first.

Private Sub Workbook_SheetChange(ByVal Sh As Object, ByVal Target As Excel.Range)
    If Range("B1").Formula = "A" Then
        Range("A1:A5").Formula = "A"
    End If
    If Range("B1").Formula = "NA" Then
        Range("A1:A5").Formula = "NA"
    End If
End Sub