I dont think you can re-train a player to become natural.
Try and keep Cole he is one of the best in the game try offering him a new contract but if you dont manage to keep hold of him try Abidal, Clichy, Bale, Marcelo, Vargas
you can train a player to become natural just takes time and he enjoys it there if he can use both feet is a bonus wont struggle as much be more adapting...
play him as a AMR as he has excellent crossing, pace etc and also has great defensive qualities to get back and win the ball while possessing the attacking skills to get forward and attack - get a great all rounded midfielder that does both jobs equally well! not like your ronaldo's or ribery's ect!