[Plugin: Shadowbox JS] loading posts with template

Hello,
I hope you can help!

I want to use the Shadowbox-js plugin to load posts individually and be able to specify the template file. So far my solution is simply a conditional argument in the single.php template to divert the template loader based on a given category.

The problem is that i can’t now use the same posts in normal single.php display.

Is there a way to pass a variable in the link indicating which template to load?