Public Sub Remplacer()
Dim derlig&, plage As Range, plg As Range, cel As Range
derlig = Range("a" & Rows.Count).End(xlUp).Row
Set plage = Range("b2:b" & derlig)
plage.Copy Range("c2")
Set plg = Range("c2:c" & derlig)
For Each cel In plg
cel = Replace(cel, ",", ".")
Next cel
End Sub