Prevent Save, enable SaveAs with default file name

hello all VBA/Excel experts, I am new to this forum and asking for your help. Here is what I am trying to do:
1) if a user clicks Save or Ctrl-S, a message should come up saying that this is not allowed, as it would overwrite the existing file (this works)
2) if a user clicks Save As, it should suggest a default file name (Consisting of a value in a cell + date) and it should save the file with either the suggested name or a new name (this does not work, a message from Step 1 comes up). Below is the code. Thank you so much for your help and have a great day.

Private Sub Workbook_BeforeSave(ByVal SaveAsUI As Boolean, Cancel As Boolean)
If SaveAsUI = False Then
   Cancel = True
    MsgBox "This would overwrite the template. Use 'Save As' instead."
    Exit Sub
    End If
SaveAsUI = True
Dim oFileDialog As FileDialog
Set oFileDialog = Application.FileDialog(msoFileDialogSaveAs)
  Dim strName As String
  Dim strDate As String
  Dim strCustName As String
  Dim strShortCustName As String
  Dim myPath As String
  Cancel = False
myPath = ActiveWorkbook.Path
strCustName = Sheet4.Range("C4")
strShortCustName = Left(strCustName, 6)
strDate = Format(Date, "Medium Date")
strName = myPath & "/" & strShortCustName & " " & strDate & ".xls"
    With oFileDialog
    SaveAsUI = True
        .InitialFileName = strName
        .Show
        .Execute
        Cancel = False
        End With
End Sub

hello shg,

1. What keeps the user from using the SaveAs dialog to save over the original file? Why not just make the file read-only?

Yes good idea, I will make it read-only. I would still like to have the message box appear if a user clicks save.

2. Once the user does a SaveAs to another filename, they are still precluded from doing a Save. Is that your intent?

This is exactly my problem. I would like the user to be able to save the file if they go through SaveAs, but not if they go through Save. Thank you.

Hello shg:

So -- the file is named "Bob". I dutifully save the file as "Joe". After that, I'm still not allowed to just press Save to resave "Joe"?

If this was possible, that would be great. The process would then be:
1. Open Bob
2. If save Bob, not allowed
3. If save as Joe, allowed
4. If save Joe, allowed
Thank you!

Dora,
I ran across this thread and it looks like what I am trying to accomplish with my spreadsheet. Did you ever get this resolved and if so what was the code you used?

Thanks