Clear a cell in an Excel Table based on choice of a dropdown validation list in the same row, while updating similar Items based on that choice

I am building a complex workbook in Excel and trying make it as user friendly as possible.

Example:
I have table call Tbltst that has three columns Control #, Dollars, and Returned.
Control # is auto populated, Dollars is user entered and Returned is a Validation drop-down.

When I change the Value from N to Y in Returned I want all the amounts in the Dollars column to change to 0 for that Control# and the other entries Returned to change to Match.

So say I change the first 1234 in the list. That $50 dollars should be blanked and Rows 3 and 6 Dollars should be blanked also and their returned column Updated to Y to match row 1.

The workbook is locked and Control# is not editable (formula driven as mentioned above) but both Dollars and Returned are editable.

I did try using formulas but to set a cell based on what is above requires a macro.

User's input in Returned column tirggers Worksheet_Change to update the data.

Worksheet.Change event (Excel)

Private Sub Worksheet_Change(ByVal Target As Range)
    Dim rngTab As Range
    Set rngTab = ActiveSheet.Range("Tbltst")
    If Not Intersect(Target, rngTab) Is Nothing Then
        With Target
            If .CountLarge = 1 And .Cells(1).Column = 3 Then
                If UCase(.Value) = "Y" Then
                    Dim sKey, c
                    sKey = Cells(.Row, 1)
                    Application.EnableEvents = False
                    For Each c In rngTab.Columns(1).Cells
                        If c.Value = sKey Then
                            Cells(c.Row, 2) = 0
                            Cells(c.Row, 3) = "Y"
                        End If
                    Next
                    Application.EnableEvents = True
                End If
            End If
        End With
    End If
End Sub