Preventing MPC-HC from opening certain filetypes when opening next/previous file?

I use the bundled MPC-HC in the K-Lite Codec to browse my large directories of .webms and .mp4s I've saved, using the playlist thingy, but within these directories are files I don't want to have opened in MPC-HC, things like audio files and .swf files (swf files in particular because no matter which ActiveX version of Flash I install it still tells me I need to install it, then it prevents me from navigating to other files). Is there any way to disable MPC-HC from automatically opening these files when I hit the next file and previous file buttons?

The Adobe Flash plugin has stopped working. You can patch it to make it work again:
https://github.com/KuromeSan/FlashPatcher/releases

To prevent the player from opening files on Next/Previous you need to edit the settings on this page:
Options > Player > Formats
You need to remove the extensions there. So not just uncheck items.

Since that is not really a good solution, it would be better to move audio files to a separate directory.