Regex find instance of dash, but not dash

Question

I am sooo close. I am trying code a regex expression for Notepad++ to replace a dash with a space, ignoring dashes already with a pre/post space. I realize I could

Answer 1

Use \w(-)\w to replace all hyphens surrounded by alphabetic characters, digits and underscores, or [^ ](-)[^ ] to replace all hyphens surrounded by non-space characters.

Both work fine in my Notepad++ version with all of your examples.