Spreadsheet Tab Control

I am looking for any help to tell me how to "map" the tab key to a specific order through unprotected cells on an excel worksheet. I have enclosed the workbook to demonstrate my request. Sheet1 (EC Template) is the "form" and Sheet2 is the map order of the cells corresponding to unlocked cells on Sheet1. I don't want the User to be taken to the shaded area to the right of the "form" though I do have to leave those cells unprotected....I want to bypass having them going to them using the tab key. Hope this is clear enough - i've included the code below that I've attempted to write but unfortunately doesn't work...:(


Private Sub Worksheet_SelectionChange(ByVal Target As Excel.Range)
'***************************************************************************************
'Tab Cell Map designed to flow through the EC Template sheet without tabbing into the
'Lookup tables.
'***************************************************************************************

'Declare Variables
Dim TabCellMap As Range, cell As Range, Fn As Object, x As Integer


Application.EnableEvents = False

'Initialize
Set Fn = Application.WorksheetFunction
Set TabCellMap = Sheet2.Cells.SpecialCells(xlConstants, xlNumbers)

x = 1

'Error Correction call
On Error GoTo errhand
If Target.Row < LastAddr.Row Or Target.Column < LastAddr.Column Then x = -1 Else x = 1

'Start the Map
n = n + x
If n = Fn.Max(TabCellMap) + 1 Then n = 1
If n < 1 Then n = Fn.Max(TabCellMap)
'Continue loop
For Each cell In TabCellMap
If cell.Value = n Then
TabAddr = cell.Address
Exit For
End If
Next cell

Sheet1.Range(TabAddr).Select
Application.EnableEvents = True

Exit Sub

errhand:
Set LastAddr = Target
Resume
End Sub

Sub enable_events()

Application.EnableEvents = True
End Sub