With Sheets("synthese")
derlig = .Range("a" & Rows.Count).End(xlUp).Row
For lig = 3 To derlig
nom = nom & .Range("b1") & " " & .Range("a" & lig)
Next
End With
For Each OlAppointment In OlItems
If OlAppointment.Subject = "RELANCE " & nom Then
OlAppointment.Delete
End If
Next
Sheets("synthese").Range("c2:c65536").ClearContents