Option Explicit
Sub Essai()
Dim s1$, s2$, c1 As String * 1, c2 As Byte, dlg&, lig&, i%
dlg = Cells(Rows.Count, 3).End(3).Row: Application.ScreenUpdating = 0
For lig = 2 To dlg
s1 = Cells(lig, 3): s2 = ""
For i = 1 To Len(s1)
c1 = Mid$(s1, i, 1): c2 = Asc(c1)
If c2 >= 48 And c2 <= 57 Then s2 = s2 & c1
Next i
s2 = "BE " & Left$(s2, 4) & " " & Mid$(s2, 5, 3) & " " & Mid$(s2, 8, 3)
Cells(lig, 3) = s2
Next lig
End Sub