public static string A1_A1(this Range rngHome)
{
var start = rngHome.A1();
var end = rngHome.A1(rngHome.Rows.Count - 1, rngHome.Columns.Count - 1);
return($"{start}:{end}");
}
public static string A1(this Range rngHome)
{
return(rngHome.A1(0, 0));
}