Auto roster to a single specific account

Hi, we have a data collection agent which is installed at numerous customers location, feeding back data to our openfire server. When a new agent is deployed i’d like to automatically roster it to one single account in both directions. i.e. agent<>server application. At the moment I have to create new users and then roster them to the application account. I know that i can automatically create accounts etc with the available plugins, but can’t work out how to roster only to one specific account.

Any help would be much appreciated.