Excel InputBox: set prefix for shape names

Question

The following code allows you to add and name shapes using an InputBox.

In this example, it adds 2 ovals to the selected range.

It has 2 Inputboxes:

• Select Shape Range

• Enter Shape Name

In the "Enter Shape Name"-InputBox, the Argument Default:="..." serves as a "prefix".

This works, but the user can edit it.

How do you build an uneditable prefix?

Option Explicit

'========================================================================
' InputBox: Add Shapes for Buttons v3
'========================================================================
' Buttons: 2
' Cell Size: Width 47
' Button Size: DIA
' Line Weight: LWT
' Shape Type: msoShapeOval, No 9
'========================================================================

Sub IPB_AddShapes_Buttons_v3()

Dim ws As Worksheet

Dim rng As Range
Dim shp1 As Shape
Dim shp2 As Shape

Const DIA As Single = 9
Const LWT As Single = 1

On Error Resume Next

Set ws = ActiveSheet

Set rng = Application.InputBox(Title:="1/3 Select Shape Range", _
                               Prompt:="", _
                               Type:=8)

  Set shp1 = ws.Shapes.AddShape(9, _
                                rng.Left + 5, _
                                rng.Top + ((rng.Height - DIA) / 2), _
                                DIA, _
                                DIA)
    With shp1
        .Name = Application.InputBox(Title:="2/3 Enter Name Level 1", _
                                     Default:="Click L1 ", _
                                     Prompt:="", _
                                     Type:=2)
        .Shadow.Visible = False
        .Fill.Visible = True
        .Fill.ForeColor.RGB = vbGreen
        .Line.Visible = False
        .Line.ForeColor.RGB = vbGreen
        .Line.Weight = LWT
        .Line.Transparency = 0
    End With
    
  Set shp2 = ws.Shapes.AddShape(9, _
                                rng.Left + 19, _
                                rng.Top + ((rng.Height - DIA) / 2), _
                                DIA, _
                                DIA)
    With shp2
        .Name = Application.InputBox(Title:="3/3 Enter Name Level 2", _
                                     Default:="Click L2 ", _
                                     Prompt:="", _
                                     Type:=2)
        .Shadow.Visible = False
        .Fill.Visible = True
        .Fill.ForeColor.RGB = vbGreen
        .Line.Visible = False
        .Line.ForeColor.RGB = vbGreen
        .Line.Weight = LWT
        .Line.Transparency = 0
    End With  
    
  MsgBox "Shape Names:" & vbNewLine & vbNewLine & _
               "" & shp1.Name & vbNewLine & _
               "" & shp2.Name, , ""
    
End Sub
'========================================================================