public partial class Form1 : Form
    {
        string selectedFile;
        int iRow, iCol = 1;
        object[,] valueArray;
        List<string> list = new List<string>();
void dowork()
        {
            Excel.Application excel = null;
            excel = new Excel.Application();
            excel.Visible = true;
            Excel.Workbook wkb = null;
            wkb = Open(excel, selectedFile);
            Excel._Worksheet sheet = wkb.Sheets[1];
           Excel.Range range1 = sheet.UsedRange;
            var arr1 = (object[,])range1.get_Value(XlRangeValueDataType.xlRangeValueDefault);
            List<object[]> listnew = new List<object[]>();
            for (int i = 10; i <= arr1.GetLength(0) - 1; i++)
            {
                if (arr1[i, 1] != null)
                {
                    if (arr1[i, 2] != null && arr1[i, 3] == null)
                    {
                        listnew.Add(new object[] { arr1[i, 1], "+ " + arr1[i, 2] + " ₹" });
                    }
                    else if (arr1[i, 2] == null && arr1[i, 3] != null)
                    {
                        listnew.Add(new object[] { arr1[i, 1], "- " + arr1[i, 3] + " ₹" });
                    }

                }
            }
            // commented out because i started adding from element 10 and also loop stops before length -1 
           // list.RemoveAt(list.Count - 1);
          //  list.RemoveRange(0, 10);         
         

            // 6. copy text file data to list 
            copydata();

            // filter from only index which conatins  names 
            Filter(listnew, 1, list); // 1 is the index number which contains names 
    }
   public void copydata()
        {
            string filename = "abc.txt.txt";
            string filePath = @"C:\hello\" + filename;
            using (var file = new StreamReader(filePath))
            {
                var line = string.Empty;
                while ((line = file.ReadLine()) != null)
                {
                    list.Add(Convert.ToString(line, CultureInfo.InvariantCulture));
                }
            }
        }
    public void Filter(List<object[]> ws, int columnIndex, List<string> values)
        {
	// compare both lists here 
        }