I am not a fan of using data connection with livecycle but to be honest, the only way I can think of is making a data connection specifically for this request...
Unfortunately I can't really tell you how to execute this kind of method because I've always worked around the data connection so the PDF works as a stand alone..
What I usually do is have hidden tables in background which hold information and then treat them with JSON objects...
but these information are public and not private, so even if users see all the information it is not an issue...
in your case you would probably need to have to work with the data connection
but before I'd tell you how to make it work I would have to do some tests myself to try to do something like this
If anyone can help you, I'd be more than interested in knowing a solution to this request!
Hope this help a bit...