.htaccess redirect help

Hi everyone.

I am currently running a multisite wordpress install with bbpress on a subsite. I want to add a redirect to .htaccess that will redirect anyone going to https://www.mywebsite.com/users/%5Busername%5D to https://www.mywebsite.com/forums/users/%5Busername%5D which I believe is possible but I am pretty bad at regex so I was hoping someone could show me the way