Приложение с различными десятичными разделителями

    
    Public SysSep = System.Globalization.NumberFormatInfo.CurrentInfo.NumberDecimalSeparator
 
    Public Function num(ByVal str As String, Optional ByVal dc As Integer = 2) As Decimal
        If str = "" Then str = 0
        If SysSep = "." Then str = Replace(str, ",", ".")
        If SysSep = "," Then str = Replace(str, ".", ",")
        If Not IsNumeric(str) Then str = 0
        num = FormatNumber(str, dc, TriState.UseDefault, TriState.UseDefault, TriState.False)
    End Function

        Dim en As New Globalization.CultureInfo(1033)
        Dim ru As New Globalization.CultureInfo(1049)
        Dim DVal As Double
                Select Case True
                    Case Double.TryParse("Значение", Globalization.NumberStyles.AllowDecimalPoint, ru, DVal)
                    Case Double.TryParse("Значение", Globalization.NumberStyles.AllowDecimalPoint, en, DVal)
                    Case Else
                        DVal = Nothing
                End Select