EasyFind - omit search results by file type (set permanently?)

Is there a way to permanently eliminate file TYPEs from all searches? I would like to keep Adobe Premiere’s .PEK files from being returned as a result when I search for audio files within my audio library.

Optionally I could specify to only search for AIF and WAV files.

That’s not possible. One option might be to use Boolean & Wildcards and to append NOT PEK to the search string.