[PascalXLD]

Re

Par macro

Sub FormatDate()
Dim x As Integer
For x = 2 To Range('A65536').End(xlUp).Row
Range('A' & x) = CDate(Left(Range('A' & x), Len(Range('A' & x)) - 4) & '/' & Mid(Range('A' & x), Len(Range('A' & x)) - 3, 2) & '/' & Right(Range('A' & x), 2))
Next
End Sub

Bon courage