Copy value from same row but other Column (variable offset) Excel VBA - vba

Question

The code below makes sure that only one of the cells in the range("D16:E25") can contain any value, when any value/string is entered in one of the other cell's within this range, the code deletes all the others. (This part works fine, thanks to "Macro Man")
Now I'd like the code to copy(and paste to "B5") a value from a certain cell in Column B, this needs to be the the cell in the same row as the value in the range("D16:E16").
Tried the folowing code you can find below... but it didn't work.
Does annyone knows a sollution for this?
I'd prefer the workbook (cell "B5") to auto update, so without having to run macro's or press buttons.
If Not Intersect(Target, Range("D16:E25")) Is Nothing Then
If Target.Cells.Count > 1 Then
MsgBox "Please edit one cell at a time!"
Else
Application.EnableEvents = False
newVal = Target.Value
Range("D16:E25").ClearContents
Target.Value = newVal
a = ActiveCell
Application.EnableEvents = True
End If
End If
If a.Column = 4 Then
Range("B5") = Range(a).Offset(0, -2).Value
Else: Range("B5") = Range(a).Offset(0, -3).Value
End If
End Sub

Answer 1

Setting up a as a Range object may be a little overkill since you already have the row by looking at the single cell target.
Private Sub Worksheet_Change(ByVal Target As Range)
If Not Intersect(Target, Range("D16:E25")) Is Nothing Then
On Error GoTo bm_Safe_Exit
Application.EnableEvents = False
If Intersect(Target, Range("D16:E25")).Cells.Count > 1 Then
Application.Undo
MsgBox "Please edit one cell at a time!"
Else
Dim newVal As Variant
newVal = Target.Value
Range("D16:E25").ClearContents
Target.Value = newVal
Cells(5, 2) = Cells(Target.Row, 2).Value
End If
End If
bm_Safe_Exit:
Application.EnableEvents = True
End Sub

Answer 2

3 Issues here:
Firstly if a is set as a Range then the correct way to do it would be
Set a = ActiveCell
Secondly, if a is set as a Range, the correct way to call it in the second if function would be
If a.Column = 4 Then
Range("B5") = a.Offset(0, -2).Value
Else: Range("B5") = a.Offset(0, -3).Value
End If
instead of
If a.Column = 4 Then
Range("B5") = Range(a).Offset(0, -2).Value
Else: Range("B5") = Range(a).Offset(0, -3).Value
End If
and thirdly the above if function should be placed between
Set a = ActiveCell
and
Application.EnableEvents = True
then your program will be run as intended when the intersect is true.