Dynamically change language without changing the regional settings

Hi everyone.

In a menu application, I turn on the “Select Language” in the “Settings” area.
The help text for this attribute is " Select the language on the bar menu.".

But the problem is, that when the user select a different language, the regional settings is also changed.
This also makes the currency of the system to change, which I do not want.

How can I make it possible for the user to change language in the menu application, without changing the regional settings?