System.Collections.IEnumerator se;
fpSpread1.ActiveSheet.AddCustomName("TwiceSum", "2*SUM(A1,A2)", 1, 1);
fpSpread1.ActiveSheet.AddCustomName("TwiceProduct", "2*A1*A2", 2, 2);
fpSpread1.ActiveSheet.SetFormula(1, 1, "TwiceSum");
fpSpread1.ActiveSheet.SetFormula(2, 2, "TwiceProduct");
fpSpread1.ActiveSheet.SetValue(0, 0, 10);
fpSpread1.ActiveSheet.SetValue(1, 0, 10);
se = fpSpread1.ActiveSheet.GetCustomNameEnumerator(false);
listBox1.Items.AddRange(new Object[] { se.MoveNext().ToString(), se.Current.ToString(), se.MoveNext().ToString(), se.Current.ToString() });