Adam,
Thank you for this. However, it does not really address my question.
What I am looking to do is simply add a parameter to a hyperlink string. When using the chain link icon to insert a hyperlink, I want to be able to add a specific parameter to the link string, in a manner similar to how you can put in your own css class for example.
Perhaps we could have a way to enter the full parameter (in this case rel="lightbox") by simply putting a text box somewhere in the link properties window as you're creating a hyperlink. I'm sure I'm not the only one who could make use of this feature. Below is what I'm thinking would work. Let me know if you agree.