using System;

using System.Collections.Generic;

using System.Text;

public class Program {

    public static void Main() {

        var worksheet = new WorkSheet();

        // Dummy WorkSheet with data

        for (var i = 0; i < 100; i++) {

            for (var j = 0; j < 75; j++) {

                worksheet.Cells[i, j] = new Cell { Value = "Value " + i + "," + j };

            }

         }

        worksheet.Cells[7, 24] = new Cell { Value = null };

        worksheet.Cells[99, 5] = new Cell { Value = null };

        var configuredColumns = new int[] { 5, 22, 24, 27, 29, 32, 34, 37, 39, 43, 45, 48, 50, 54, 56, 59, 61, 65, 67, 71, 73 };   

​

        // loop over all data rows (ignore first 5 rows which are headers)

        // stop looping if the current row has no data in column 5

        var allRowTexts = new List<string>();

        for (int row = 5; worksheet.Cells[row, 5].Value != null; row++) {

​

            // loop over the configured columns

            var rowText = new StringBuilder();

            foreach (var col in configuredColumns) {

​

                var cell = worksheet.Cells[row, col];

                if (cell.Value == null) {

                    rowText.Append("leer" + "\t");

                }

                else {

                    rowText.Append(cell.Value.ToString() + "\t");                

                } 

            }

​

            // rowText now contains all column values for the current row

            allRowTexts.Add(rowText.ToString());

        }

​

        // write all rows to console

        foreach(var row in     allRowTexts) {

            Console.WriteLine(row); 

        }

    }

}

​

// Dummy WorkSheet

public class WorkSheet {

    public WorkSheet() {

        Cells = new Cell[100, 75];

    }

    public Cell[,] Cells;   

}

​

// Dummy WorkSheet Cell

public class Cell {

    public string Value;

    public override string ToString() {

      return Value; 

    }

}