how to apply regional settings of server when uploading excel

Before applying the regional settings of server, you need to retrieve the culture information. You can use the CurrentCulture to obtain the fresh values of the culture. Here is the sample code:

class Program
{
    private class State
    {
        public CultureInfo Result { get; set; }
    }

    static void Main(string[] args)
    {
        Thread.CurrentThread.CurrentCulture.ClearCachedData();
        var thread = new Thread(
            s => ((State)s).Result = Thread.CurrentThread.CurrentCulture);
        var state = new State();
        thread.Start(state);
        thread.Join();
        var culture = state.Result;
        // Do something with the culture
    }