Custom Magento Extension which allows to be connected and call Mage API externally from a remote server

The project needs a magento extension that would allow external calls to the system with the ability to make updates in the magento's core_config_data table. through some calls ex: ( Mage::getModel('core/config')->saveConfig('path/to/config', 'value');) or even with REST or SOAP if that is even possible. the main thing here is the core config data. It is possible avoid extension and do it directly through a MySQL connection, but it would be nice to stick with the normal practices when possible dealing with Magento. The goal is to accomplish some back office updates programmatically/automatically down the road. (to remotely call and update default designs or add/update static blocks in the backend) and maybe more in the future. The reason which I need it remotely is because I will be calling it externally from a remote site and help manage the website through other scripts and cron jobs, so it would be better if the extension code is created in a more dummy proof way for easier edits with method calls in the future. This is an initial plan for the extension, so if there may be some difficulty doing it simply because Magento limitation itself, please feel free to contact me to further discuss other methods or even more simple solution to what the project wants to achieve.