leggere un valore dalla radgrid on ItemCommand

Protected Sub RadGrid1_ItemCommand(ByVal source As Object, ByVal e As Telerik.Web.UI.GridCommandEventArgs) Handles RadGrid1.ItemCommand

        Dim action As String = e.CommandName

        If (action = "XXX") Then

            Dim id As Integer = e.CommandArgument

            Dim item As GridItem = DirectCast(e.Item, GridItem)
            ' definire l'oggetto da leggere
            Dim campo As HiddenField = DirectCast(DirectCast(item, Telerik.Web.UI.GridDataItem).FindControl("hiddenCampo"), HiddenField)

            'definire il tipo di dato i uscita
            Dim valore As String = campo.Value

        End If

    End Sub