Sub Macro1()
Dim LeC As Double, TpC As Double, HeC As Double, WiC As Double
Dim HeS As Double, WiS As Double
LeC = ActiveCell.Left 'position haut
TpC = ActiveCell.Top 'position gauche
HeC = ActiveCell.Height 'hauteur
WiC = ActiveCell.Width 'largeur
With Selection
HeS = Selection.Height 'hauteur
WiS = Selection.Width 'largeur
.Top = TpC + ((HeC - HeS) / 2)
.Left = LeC + ((WiC - WiS) / 2)
End With
End Sub