Within ArcMap, is there a way to indicate what features to label via a "select by location" method instead of a SQL query?

I would normally approach the issue by adding an additional field in the feature class' attribute table, then populate it with something like a "Y" or "N" based on the features' location, indicating whether or not the feature should be labeled. However, in this instance, the feature class' attribute table is not editable and a new feature class cannot be exported.