Interdire l'utilisation des touches suppr et del dans une cellule

If Intersect([I4:I300,K4:K300,U4:U300], Target) Is Nothing Or Target.Count > 1 Then Exit Sub

Sub DesactiveSUPPR()
Application.OnKey "{DEL}", ""
End Sub

Sub ActiveSUPPR()
Application.OnKey "{DEL}"
End Sub

Private Sub Worksheet_Change(ByVal Target As Range)
Memorise Target, [I4:I300], "Zone1"
Memorise Target, [K4:K300], "Zone2"
Memorise Target, [U4:U300], "Zone3"
End Sub

Sub Memorise(Target As Range, plage As Range, zone$)
If Intersect(Target, plage) Is Nothing Then Exit Sub
Dim i, cel As Range
Application.EnableEvents = False
For i = 1 To plage.Count
  Set cel = plage.Cells(i)
  If Not (Intersect(cel, Target) Is Nothing Or IsNumeric(cel.Formula)) _
    Then cel = Application.Index(Evaluate(zone), i)
Next
ThisWorkbook.Names.Add zone, plage.Formula 'mémorise
ThisWorkbook.Names(zone).Visible = False 'masquage facultatif
Application.EnableEvents = True
End Sub

Private Sub Workbook_Open()
Me.Names.Add "Zone1", [I4:I300].Formula
Me.Names.Add "Zone2", [K4:K300].Formula
Me.Names.Add "Zone3", [U4:U300].Formula
'---masquage facultatif---
Me.Names("Zone1").Visible = False
Me.Names("Zone2").Visible = False
Me.Names("Zone3").Visible = False
'---évite le message à la fermeture---
Me.Saved = True
End Sub

If Not (Intersect(cel, Target) Is Nothing Or IsNumeric(Evaluate(cel.Formula))) _

If Not Intersect([I4:I300,K4:K300,U4:U300], Target) Is Nothing And Target.Count = 1 Then
  Dim valsaisie
  On Error Resume Next
  Application.EnableEvents = False
  valsaisie = Target
  Application.Undo
  Target = IIf(Target.HasFormula, Target.Formula & "+", "=") & valsaisie
  Application.EnableEvents = True
End If

If IsNumeric(Evaluate(Target.Formula)) Then