How can we find Perticular Modem Port in Cpu(System)

private bool EnterNewSettings()
{
    int newPort=0;
    int newBaudRate=0;
    int newTimeout=0;
    int count = 0;
    string[] strport;
    string[] strbaudrate;
    string[] strtimeout;
    try
    {
        strport = Convert.ToString(ConfigurationSettings.AppSettings["COMPortID"]).Split(',');
        strbaudrate = Convert.ToString(ConfigurationSettings.AppSettings["COMBaudRATE"]).Split(',');
        strtimeout = Convert.ToString(ConfigurationSettings.AppSettings["COMTimeOUT"]).Split(',');

    }
    catch (Exception es) { return false; }

    bool comStatus;
    bool comMTN = true;
    int comPortNonMTN = 0;
    if (count != 1)
    {
        for (int i = 0; i < strport.Length; i++)
        {
            comStatus = true;

            for (int j = 0; j < strbaudrate.Length; j++)
            {
                for (int k = 0; k < strtimeout.Length; k++)
                {
                    try
                    {
                        newPort = int.Parse(strport[i]);
                    }
                    catch (Exception)
                    {
                        AddToLog("Invalid port number");
                        return false;
                    }

                    try
                    {
                        newBaudRate = int.Parse(strbaudrate[j]);
                    }
                    catch (Exception)
                    {
                        AddToLog("Invalid baud rate");
                        return false;
                    }

                    try
                    {
                        newTimeout = int.Parse(strtimeout[k]);
                    }
                    catch (Exception)
                    {
                        AddToLog("Invalid timeout value");
                        return false;
                    }

                    SetData(newPort, newBaudRate, newTimeout);
                    GsmCommMain comm = new GsmCommMain(port, baudRate, timeout);
                    try
                    {
                        if (comStatus)
                        {
                            comm.Open();
                            comStatus = false;
                            Thread.Sleep(20000);
                            if (!comm.IsConnected())
                            {
                                //AddToLog("Not Connected : Port - " + port);
                                comm.Close();
                                //return false;
                            }
                            else
                            {
                                if (comMTN)
                                {
                                    comm.Close();
                                    comMTN = false;
                                    comPortNonMTN = i;

                                    i = strport.Length + 1;
                                    count = 1;

                                    return true;

                                }
                                else
                                {
                                    AddToLog("Connected: Port - " + port);
                                    comm.Close();
                                    return true;
                                }
                            }
                        }
                    }

                    catch (Exception ex)
                    {
                        //AddToLog("Connection error: " + ex.Message);
                        //return false;
                    }
                }
            }
            if (i + 1 == strport.Length)
            {
                i = comPortNonMTN - 1;
            }
        }
    }
    return false;
}