Lock cells / ranges to an existing VBA code to create editable areas and allow VBA to run

I haven't used VBA before so I'm really new to this :-) The below is the code I am currently using , and simply need to lock all area's of the sheet (with out using the sheet name) apart from A13:A377, B1, D3:D4, D13:D377, F13:I377. I can't protect the sheet because the VBA won't work. Help please...

Private Sub Worksheet_Change(ByVal Target As Range)
' To allow multiple selections in a Drop Down List in Excel (without repetition)
Dim Oldvalue As String
Dim Newvalue As String
Application.EnableEvents = True
On Error GoTo Exitsub
If Target.Column = 1 Then
If Target.SpecialCells(xlCellTypeAllValidation) Is Nothing Then
GoTo Exitsub
Else: If Target.Value = "" Then GoTo Exitsub Else
Application.EnableEvents = False
Newvalue = Target.Value
Application.Undo
Oldvalue = Target.Value
If Oldvalue = "" Then
Target.Value = Newvalue
Else
If InStr(1, Oldvalue, Newvalue) = 0 Then
Target.Value = Oldvalue & " & " & Newvalue
Else:
Target.Value = Oldvalue
End If
End If
End If
End If
Application.EnableEvents = True
Exitsub:
Application.EnableEvents = True
End Sub

Try it:
1. In worksheet module (full code):

Please Login or Register  to view this content.

2. In ThisWorkbook module:

Please Login or Register  to view this content.

3. Save and reopen this workbook.

Artik