exclude external email address while including multiple custodians

I need to conduct a search in DA 10.0 for emails sent to or from a long list of custodians, while excluding any to or from one external email address. I've tried many different approaches but can't get any that work.

If I were to write it out as a string, I'm looking for something like the following.

To or from: (C:John Kennedy OR C:Harry Truman OR C:Theodore Roosevelt) AND NOT (HelenThomas@gmail.com)

Any advice would be appreciated.

Thanks,

David