If most of your international calls are to one country with a fixed dialing format, you could set a custom digit map to recognize those number and send the call immediately. For frequently called numbers, you could also use OBi speed dials (e.g. dial 2#) or Callcentric speed dials (e.g. dial *7501). For the latter, you would need to modify the digit map to send *75xx to Callcentric.