Configure languages for desktop in the shell?

[Dennis Knorr <dennis.knorr@xxxxxxx>]

Hello,
i want to configure the desktop language not in system settings, but in
the shell, is this possible?

More precisely, i want to add 2 languages, and set another one (not
english/american) as the top one for language, format, konsole, time and
so on.

Is there a possibility to do that?

Kind regards,
Dennis Knorr