Apply VBA macro to subsequent rows - excel

Question

I am trying to clear the contents of some cells if the value in a corresponding cell changes.
In the code below, if the value in O1 changes, the contents of Z1 to AD1, and P1 are cleared.
How can I apply this to all rows below, i.e. if O2 changes, the contents of Z2 to AD2, and P2 should be cleared, the same thing for row 3 and so on.
I'd like if new columns/rows are inserted in the worksheet, things won't break.
Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Address = "O1" Then
Range("Z1:AD1").ClearContents
Range("P1").ClearContents
End If
End Sub

Answer 1

This should get you started
Only looks for changes that occur in Column O
Only triggers if ONE cell is changed at a time.
(you will need to switch to loop if many cells in Column O can be changed in one action such as pasting a range)
Be sure to turn events OFF before making any other changes to worksheet else you will end up in infinite loop leading to your instance of excel crashing
Make dynamic by clearing cells that are on the same row as the changed cell i.e. Target.Row
Private Sub Worksheet_Change(ByVal Target As Range)
If Not Intersect(Target, Range("O:O")) Is Nothing Then
If Target.Count = 1 Then
Application.EnableEvents = False
Range(Cells(Target.Row, "Z"), Cells(Target.Row, "AD")).ClearContents
Cells(Target.Row, "P").ClearContents
Application.EnableEvents = True
End If
End If
End Sub

Answer 2

This should work.
Private Sub Worksheet_Change(ByVal Target As Range)
tCol = Target.Column
tRow = Target.Row
If tCol = 15 Then
For i = tRow To tRow + Target.Rows.Count - 1
Range(Cells(i, 26), Cells(i, 30)).ClearContents
Cells(i, 16).ClearContents
Next
End If
End Sub
Use Target.Column and Target.Row to get the number of the targets column and row which can then be used in Cells().