redirect www to http AND root to subdirectory in .htaccess

Basically I found separately ways of redirecting www to non www AND ways of redirecting root to subdirectory.

But when I put them together in htaccess it doesn't seem to work (they work separately but not together)

I want to be able for instance to redirect http://www.example.com (with www) to http://example.com/fr (without www, and subdirectory)

What should I do to fix both issues ?

Thank you ! :)