how to open different cell of excel file in a text box on every click of button in desktop application

//Attach click event of button to the click event handler
NextWord.Click += NextWord_Click;

//Declare fields to hold the excel rownumber and cell addresses
int rowNumber;
string germanCell;
string englishCell;


OpenFileDialog openexcel = new OpenFileDialog();


//Initialize the row number
rowNumber = 2;
                openexcel.Title = "Mayank";
                openexcel.InitialDirectory = @"c:\";
                openexcel.RestoreDirectory = true;
                openexcel.DefaultExt = ".xls";
                openexcel.Filter = "xls files (*.xls)|*.xls|All files (*.*)|*.*";
                openexcel.FilterIndex = 2;
                if (openexcel.ShowDialog() == DialogResult.OK)
                {
                    Excel.Application xlApp;
                    Excel.Workbook xlWorkBook;
                    Excel.Worksheet xlWorkSheet;
                    object filename = openexcel.FileName;
                    object misValue = System.Reflection.Missing.Value;
                    xlApp = new Excel.ApplicationClass();
                    xlWorkBook = xlApp.Workbooks.Open(filename.ToString(), misValue, misValue, misValue, misValue, misValue, misValue, misValue, misValue, misValue, misValue, misValue, misValue, misValue, misValue);
                    xlWorkSheet = (Excel.Worksheet)xlWorkBook.Worksheets.get_Item(1);
                    //xlApp.Visible = true;

           
//Populate the text boxes with the first values
                    CreateCellAddresses();
                    txtsearchgerman.Text = GetTextFromExcel(germanCell);
                    txtsearchenglish.Text = GetTextFromExcel(englishCell);

                    xlWorkBook.Close(true, misValue, misValue);
                    xlApp.Quit();
                    xlApp = null;



//Define a method to handle the click event of the NextWork button
private void NextWord_Click(object sender, EventArgs e)
{
//Increment the rownumber
    rowNumber++;
//Create cell addresses
    CreateCellAddresses();
//Populate the text boxes with the words from the next row of the excel
    txtsearchgerman.Text = GetTextFromExcel(germanCell);
    txtsearchenglish.Text = GetTextFromExcel(englishCell);
}
//Define a method to create cell addresses of the next words
private void CreateCellAddresses()
{
    germanCell = string.Format("A{0},A{0}",rowNumber);
    englishCell = string.Format("B{0},B{0}",rowNumber);
}
//Define a method to get the text from excel cell
private string GetTextFromExcel(string cellAddress)
{
    return (xlWorkSheet.get_Range(cellAddress).Value2.ToString());
}