How to filter Datagridview From Another Datagridview c#

Question

I am looking for a way to filter Datagridview to another Datagridview and by using a reference number in the first column and searching for a sum of the values of this reference number in another column

Look at the pictures below to understand what I'm looking for:

Datagridview 1

 

 

For datagridview 1 in doesn't have any data table or database just get data from some text boxes

Datagridview 2

 

For datagridView 2 i Just filled it manually, So i want to do it automatically.

can someone help me..? thanks.

sorry for my bad english.

This is my code

namespace SAMPLE
{
    public partial class Form2 : Form
    {
        public Form2()
        {
            InitializeComponent();
        }
        private void add_Click(object sender, EventArgs e)
        {
            int n = dataGridView1.Rows.Add();
            dataGridView1.Rows[n].Cells[0].Value = txtReff.Text;
            dataGridView1.Rows[n].Cells[1].Value = txtProd.Text;
            dataGridView1.Rows[n].Cells[2].Value = textPrice.Text;
            dataGridView1.Rows[n].Cells[3].Value = txtNumber.Text;
            dataGridView1.Rows[n].Cells[4].Value = txtSum.Text;
        }
        private void textHt_TextChanged(object sender, EventArgs e)
        {
            try
            {
                txtSum.Text = (double.Parse(textPrice.Text) * double.Parse(txtNumber.Text)).ToString();
            }
            catch
            {
            }
        }
        private void txtFrs_TextChanged(object sender, EventArgs e)
        {
            try
            {
                txtSum.Text = (double.Parse(textPrice.Text) * double.Parse(txtNumber.Text)).ToString();
            }
            catch
            {
            }
        }
    }
}