android - changing the system settings of a rooted device from inside the app

I am trying to change the sms limit described here from inside the app. The app is assumed to be running on a rooted device. I'm using the RootTools to check if the device is rooted or not. I'm trying to figure out how to write the actual setting on to the settings.db. Any suggestion which could help me in this is highly appreciated.

Thanks in advance.

Solution

I got this solved by doing this:

copy the /data/data/com.android.providers.settings/databases/settings.db to my application folder /data/data/my_app_directory/.
update the table in the database using the SQLiteDatabase class.
copy back the database from /data/data/my_app_directory/settings.db to /data/data/com.android.providers.settings/databases/

The copy operations were done by using RootTools.sendShell