TOPIC: How to change currency and lunguage.

I want to know how to change currency from dollar to another, such as JPN (Japanese Yen).
I translated language file to Japanese, jp-JP.com_quicksell,ini, jp-JP.com_quicksell.sys,ini, and jp-JPN.mod_quicksellcart.ini in each language folder ja-JPN newly-made, but they are not selected. Why?