Custom Title Tags - revisited

What is the code syntax if I want my Title Tag to dynamically look like this:

Rings | Sapphire Rings | Large Sapphire Ring - MySite Name

For this URL: www.mysite.com/rings/sapphire-rings/large-sapphire-ring
I want to use the Category, Subcategory, Product Name , and Site Name to populate the Title tag.

There is another thread similar over here:
http://forum.opencart.com/viewtopic.php ... 76#p216176

But, it doesn't answer my question.
Any help will be much appreciated.