I suppose you could use the flight number isolation approach mentioned above, and only include the flight numbers in the range of the partner you're targeting.
You can also use a tilde to exclude just about anything you can include. So, for example, to exclude Continental-operated flights, you can use ~O:CO . The catch with the O: and ~O: operators is that commuter flights often aren't listed under the main airline's code. For example, specifying O:NW won't get you flights on Northwest Airlink, which might be operated by 9E or XJ.
