How can I extract a string between two character using C#?

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var staMgrParaInf = new Array(1,0,0,0,10,48,2,1,0,0,0 );
</script><script language=JavaScript>var staEntryInf = new Array("192.168.1.56",0,87357,111282,10432836,103871290,1,1,41,52,"192.168.1.21",0,394,42991358,55037052,5,7,260,10360);</script>
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    var pageRefreshTime = 10;

"192.168.1.56",0,87357,111282,10432836,103871290,1,1,41,52,
"192.168.1.21",0,39439,42063,2991358,55037052,5,7,260,10360

private void button1_Click(object sender, EventArgs e)
{
    String line;
    String filetext = null;
    int count = 0;
    using (System.IO.StreamReader reader = new System.IO.StreamReader("C:\\viewsource.txt"))
    {
        while ((line = reader.ReadLine()) != null)
        {
            if (count == 0)
            {

                if (line.StartsWith("<"))
                {

                }
                else
                {
                    filetext = filetext + line;
                }
            }
            else
            {
                if (line.StartsWith("<"))
                {

                }
                else
                {
                    filetext = filetext + "\n" + line;
                }
            }
            count++;
        }
        Trace.WriteLine(filetext);

        int start = filetext.IndexOf("(") + 1;
        int end = filetext.IndexOf(")", start);
        string result = filetext.Substring(start, end - start);
        textBox1.Text = result;
        reader.Close();
    }
}

1,0,0,0,10,48,2,1,0,0,0

"192.168.1.56",0,87357,111282,10432836,103871290,1,1,41,52,
"192.168.1.21",0,39439,42063,2991358,55037052,5,7,260,10360