You can apply Integrated GARCH model which consider the long memory process in the conditional variance using Eviews. There are also codes for fractionally Integrated GARCH models including ARFIMA-GARCH and FIGARCH in Matlab GARCH Toolbax. You can also use a new model recently introduced by Kilic (2011), called, the Smooth transition FIGARCH (ST-FIGARCH) using Matlab, which can jointly capture the long memory process and the nonlinearity in the conditional volatility process.