Send (Pass) Hash (#) in Query String in ASP.Net

i am trying to pass below value Star Order #8

In GridView to another page. It is pass just Star Order, not sending complete value on row selection

protected void GVOrderstatus_SelectedIndexChanged(object sender, EventArgs e)
{
    //Response.Redirect("OrderDetailUDI.aspx?Ref_No=" + GVOrderstatus.SelectedRow.Cells[2].Text);
    string Order_Ref_No = GVOrderstatus.SelectedRow.Cells[2].Text;
    Response.Redirect("ODUpdateinsert.aspx?Order_Ref_No=" + Order_Ref_No);
}