Ummmm, please don't cheat. There is no satisfaction in winning if you had to cheat to do it, especially if your opponent finds out about it. That isn't what this game is about.
If you have Emerald, the fastest way to gain Exp (besides stuffing your Pokes full of the candies), is to battle Gabby & Ty (the reporter and cameraman) that move around from Route 111 to Route 118 to Route 120). Put a high level Poke with EQ in the lead with the Poke you want to level up in the second slot, holding Exp Share. Start the battle, select EQ with the first Poke, and then switch out your second Poke with a different Poke that is either part Flying-type or has Levitate, holding an Amulet Coin. EQ will OHKO Maggie and seriously (if not fatally) damage Exploud. Attack again, if necessary, to win the battle. Now, since your second Poke was holding the Exp Share and then switched out, it will get 75% (1664 Exp points) of all Exp earned during that battle, while your first Poke and replacement Poke end up splitting the remaining 25% (554 Exp points). Not only that, but since your replacement Poke was holding the Amulet Coin, you get twice the money for winning (5760 Pokebucks). Now consider that you can do that an infinite number of times, and you don't have to wait for the game to reset to go anywhere, the way you have to at the E4. Overall it gives you more Exp and more money in the same amount of time.
As for your team, as AB suggested, please post your team (and your opponent's if you know it) in the Moveset forum and we can assist you in how to create your team and give you strategy on how to beat your opponent.
