How to use Trace

[mce]

I want to use trace to file.

  FileStream Log = new FileStream("Log.txt", FileMode.OpenOrCreate);

      Trace.Listeners.Add(new TextWriterTraceListener(Log));
      Trace.WriteLine("My Trace String To Log File");
      Trace.Flush();
      Log.Close();

The problem with the above codes is trace will always log to the file Log.txt.
How to call Trace with the file handler itself??, so that i can specify which file to log to when i do a Trace.

I tried using traceSource like the following, but it doesn';t work as well., the information is not even logged into file!!

     {
                string l_path = String.Format("c:\\mylog_{0}.txt", this.GetHashCode());
                _log = new FileStream(String.Format(l_path), FileMode.Append);

            }
            if (_traceSrc == null)
            {
                _traceSrc = new TraceSource(this.GetHashCode().ToString());
                _traceSrc.Listeners.Add(new TextWriterTraceListener(_log));
                _traceSrc.TraceInformation(String.Format("Hello from {0}", GetHashCode()));