Changed default directionality in Drupal TinyMCE module

Hi,

Two questions:

1: How can I change the default directionality of TinyMCE with Drupal module? According to the following link:

http://wiki.moxiecode.com/index.php/TinyMCE:Configuration/directionality

I just need to change the TinyMCE configuration file with this:
tinyMCE.init({
...
directionality : "rtl"
});

Since TinyMCE configuration is kept in MySQL tinymce_settings table and there is no option in /admin/settings/tinymce, what is the proper way to add this line?

2. I know there is RTL and LTR button in TinyMCE but is there any way to create another button to apply RTL function to the whole page? The new button will wrap the entire HTML page under the following CSS tag:

LTR and RTL button applies to certain HTML blocks not to the entire page and I need a solution to switch directionality for the entire page.

Thanks,
--Nader