Template language has a function called has_extra_files(). You can leverage this doing the following template search (copy paste into calibre search bar):
Code:
template:"""program:
if has_extra_files() then 'yes' else 'no' fi#@#:t:yes"""
A little slow because it uses templates, but it gets the job done. If you are going to use it often, it is a good idea to make this a saved search.