Are you using CPanel/WHM? If so maybe you can add further MYSQL Hosts? Some hosting companies allow this. You can find this option in CPanel / Databases / Remote MySQL (and add your server IP).
Or maybe go with localhost on both the testing server and the remote server then that way there are no configuration issues?
Or you could manually edit the DMX Connection file on the remote server to localhost? Assuming the site is hosted on the same server as the database?