I want to change region of my account but still have an Apple balance

Nobody on these boards can. Buy something more expensive than your balance and use a different payment method from the current region for the excess amount; if you can't, click here and ask the iTunes Store staff to zero it.

If you're referring to another store, check its documentation.

(242100)

You can do what @Niel said, or you're purchasing cheap stuff like an App or a song.