None....It's impossible, sorry.
However, in HG/SS, you can get an ExtremeSpeed Dratini. Here's how :
> #147 Dratini
After you have defeated Clair in the Blackthorn Gym, she will send you on a quest into the Dragon.s Den. Deep inside the den you will discover a building with the elders. These Elders will ask you questions about how you raise your Pokémon. After the questions are answered, he will give you a Dratini. If you answer his questions with the compassionate responses, the Dratini will know the special move; ExtremeSpeed. If you don't answer with those responses, it will just know its basic moves.
--Serebii.
So get this ExtremeSpeed Dratini, and trade it, or migrate and then evolve.... That's the only legit way.
Hope This Helps :)
