J'ai ça :
Sub userForm_Initialize()
Dim i As Integer, last_row As Integer, last_column As Integer
Dim my_control
last_column = ThisWorkbook.Sheets("LEAP 1B v2").Range("B5").End(xlToRight).Column
last_row = ThisWorkbook.Sheets("LEAP 1B v2").Range("B5").End(xlDown).Row
MsgBox last_column 'calcul nb colonne
MsgBox last_row 'nb ligne
'If last_column = last_row Then 'verification que nb ligne = nb colonne (en attente de modif dufichier initial
For i = 3 To last_column
Set my_control = Frame1.Controls.Add("Forms.checkbox.1", "Label" & i, True) 'ajout d'un nouveau checkbox dans le frame
With my_control 'ajout du texte de sa position et de sa forme ...
.Caption = " " & Sheets("LEAP 1B v2").Cells(5, i).Value
.Top = -10 + 23 * (i - 2)
.Left = 20
.Width = 250
End With
Next i
Frame1.ScrollHeight = Frame1.Controls.Count * 23.15 'hauteur scrollbar
'End If
End Sub