HTTP and HTTPS in one app

Hi,

I am building an application where I need to use HTTPS for most of the of the application and HTTP for the rest of the application. My SSL Certificate is tied only to the subdomain MY (my.newapp.com). So https://my.newapp.com will be the secured part and http://www.newapp.com and http://newapp.com will be the unsecured part.

What changes would be needed in the various configuration files (HTACCESS, CONFIG.PHP, etc.)?

Any help would be appreciated!