Make sure to replace example\.com with the domain name you're trying force to https. Additionally, you need to replace www.yourdomain.com with your actual domain name.
If you want to force SSL on a specific folder you can insert the code below into a .htaccess file placed in that specific folder:
Make sure you change the folder reference to the actual folder name. Then be sure to replace www.yourdomain.com/folder with your actual domain name and folder you want to force the SSL on.