I have a working file here that will work if the url appears in a single line, not within body text. I’m not sure how this could be hoodwinked into a workable reflowing of text scenario.
But this is how I’d start attempting it.
IDML file
https://dl.dropboxusercontent.com/u/17210757/Test%20Interactive%20Hyperlink.idml
Working PDF
https://dl.dropboxusercontent.com/u/17210757/Test%20Interactive%20Hyperlink.idml
I made a separate text frame and put in “Click here to find out more!”
And in the text frame it says “www.google.com”
I then anchored the text frame with “Click Here to Find out More!”
And made that an interactive button.
The interactive button is anchored above the the text in the text frame.
I then set the Interactive Button to not print via it’s dialog.
And now you see the text in the PDF “Click here to find out more!” but it prints “www.google.com”
Let me know if you need any more information on this technique.