Change language setting through script?

Hi all,
Does anyone know if it’s possible to change the language settings?
Here’s my problem:
I have the two languages I use regularly, and a third one which I use only about once a week.
That third one most of the time gets in my way.
I want a script (or two separate ones) to add/remove it from the selected languages in my preference pane.

Thanks all.
hizki