You can do something like this sequence.
Turning Error Capture on prevents the Modify Find error box. Perform the Find and then turn Error Capture off. Use the Get(FoundCount) to determine if any records were returned. You can enclose it in an IF statement then to take different actions depending on if records were returned or not.
Get(FoundCount) is located under the "Get Functions" selection of the View option (upper right corner) of the Calculations window.
Aha! Thanks a million - you've both rid me of quite a headache!