You really just need to get your face known and to get in with a Senior Exec (not essential they are in Strategy) who feels able to sponsor you.While I cant offer a fail safe solution I would say its important to demonstrate your desire to move into Strategy to everyone you encounter in the organisation. Talk about it, explain it, demonstrate it, show passion and approach all the work you are given with a "strategy" mindset. Hopefully then any potential you have will be recognised.