Just giving this to others as I have spent the past 3 days learning regular expressions and attempting to make this work.
Action Type: Format Value Field: ARTIST Format String: $regexp(%_Path%,.*\\\\Music\\\\(\w+).*,$1)
Since my music directory is really organized I can pull a lot of info straight from my directory path. This line here pulls the folder name after the \Music\ folder and stores it in the ARTIST tag.