Never mind.. did it through WatiN :)
after adding a reference to the project.. i used the mentioned code
private void btnComplete_Click(object sender, EventArgs e)
{
try
{
lblStatus.Text = "";
string[] Orders = txtOrders.Text.Split('\n');
foreach (string text in Orders)
{
// locate the Order Number (Completer)
browser.TextField(Find.ByName("txt_comp_order")).Value = text;
browser.Button(Find.ByName("Button2")).Click();
}
lblStatus.Text = Orders.Length.ToString() + " Order(s) COMPLETED";
}
catch (Exception ex)
{
MessageBox.Show(ex.ToString());
}
}