Sub Conversion()
Dim t, ds$, tablo, ub%, i&, j%, x$
t = Timer
ds = Application.DecimalSeparator
With [A1:BH25000] 'à adapter
tablo = .Formula 'au cas où il y aurait des formules
ub = UBound(tablo, 2)
For i = 1 To UBound(tablo)
For j = 1 To ub
x = Replace(tablo(i, j), ".", ds)
If IsNumeric(x) Then tablo(i, j) = CDbl(x) 'conversion
Next j, i
.Value = tablo 'restitution
End With
MsgBox Timer - t
End Sub