Can preview button behavior be easily adjusted a bit?

Hallo everyone!

I'd like to customise my FCKeditor installation. I like the 'Save' button behavior, as it just submits the form that the editor is surrounded by. Logical and straightforward.

But I don't like the 'Preview' behavior. As my editor will NOT be working in a fullpage mode, I'd rather like the preview button to open up a popup and submit the form data to some specified php script, like /pages/preview. This would give me the opportunity to present the user-submitted content using the full layout, giving her/him an easy way to see how it will look before he/she decides to click 'Save'.

I'm not very familiar with the newest FCKeditor (I'll be using the latest stable release). Is it possible to change this behavior in a few LOC, without doing any harm to the core JS and possibly breaking up the possibility of a trouble-free future updates? Or maybe the only way here is to write a plugin replacing the original 'Preview' button?

Would be really grateful for your help and suggestions.

Greetings from Poland,
Piotr