Redirect http to https, non www to www and main site to subfolder with htacess

I am trying to redirect my site to use https, www and subfolder redirect but I am failing to do so. I want multiple access codes, means a code that can redirect HTTP to https, non-www to www and main site to subfolder at the same time.

I want to redirect all the main domain traffic of https://nokiamobile.co.uk to https://www.nokiamobile.co.uk/forums

How can I do that with .htaccess in the root folder of the domain?