I took a long break from webdesign but recently jumped back into it. I'm building a website and installed a SSL cert for my shopping cart but I have a problem.

Is there a way to prevent or redirect a person to another page if someone attempts to load https outside my store directory?

So basically I want https://www.mydomain/store/ to work, but I don't want https://www.mydomain.com to work because I have non-secure links and people going there will have problems if they add the s. I'm also affraid of duplicate content problems if search engines see the website under https also.

I don't know if the problem is with the SSL cert, or with htaccess, or something I'm missing all together.