Excluding external volumes from search

I have a markdown file which contains a ton of links in this format (note the opening and closing tags):

[Some File](</Volumes/folder/somefile.mp4>) 

I need to keep the link formatting, but I don’t want these links filling up the Quick Switcher and autocomplete. I’ve tried different syntaxes in “Exclude Files” but nothing works.

I only need to exclude files starting with /Volumes/folder/.