How do I read extra lines of a text file in addition to my DataGridView?

private void open(object sender, EventArgs e)
{
    // only works for opening the table
    dataGridView1.Rows.Clear();            
    OpenFileDialog openDialog = new OpenFileDialog();

    if (openDialog.ShowDialog() == DialogResult.OK)
    {
        fileLabel.Text = openDialog.FileName;

        // Use File.ReadAllLines, it's easier
        string[] lines = File.ReadAllLines(openDialog.FileName);

        foreach (string line in lines)
        {
            var text = line.Split(',', '\n');
            dataGridView1.Rows.Add(text);
        }

        for (int i = 0; i < dataGridView1.Rows.Count; i++)
        {
            dataGridView1.Rows[i].HeaderCell.Value = (i + 1).ToString();
        }

    }
}

The above code works well. However, what's the problem is that it does not support reading extra lines after this and adding the text towards some controls in Windows Forms.

int k = 0;
while (k < lines.Length)
{
    for (int j = 0; j < twoDTextBox.GetLength(0); j++)
    {
        for (int i = 0; i < twoDTextBox.GetLength(1); i++)
        {
            statsBonus[j, i].Text = lines[k];
            k++;
        }
    }

    // these lines I would like to add to read in my new file
    textBox1.Text = lines[k];
    k++;
    comboBox1.SelectedItem = lines[k];
    k++;
    checkBox1.Checked = Convert.ToBoolean(lines[k]);
    k++;
}

This code is my previous version of reading a text file and adding it towards the controls. This was used before I thought about using datagridview. I used text boxes array 2d instead.

Now I want to try and add a feature that can read extra lines of my text file and place them on another control instead of datagrid view. How do I do that and make sure it doesn't get the wrong data on the wrong controls?