Wow'ee I've no idea. However if you have looked at the photoreading forum you will have noticed that people have photoread language books many times before a visit abroad and have surprised themselves with how much they understood what was said to them and their own replies in another language. What I'm saying is it must be possible, you have nothing to lose. With the GC you can try out the Borrowed genius technique(Borrowing another head), to learn the secrets of understanding new languages. Improve your study techniques using some of the techniques described by Win Wenger on his web site (WinWenger.com). Also have you tried Paul Scheele's paraliminal tape series called EasyLearn Language Programs. I believe this series incorporates mind mapping with visual material in a book with paraliminal tapes for relaxing and letting the subconcious learn new words and grammer easily.
I hope this above gives you some ideas and the direction you can take to achieve your goal. If you follow other GC techniques I think you'll find that even better ideas will suggest themselves to you.
Good luck
Keren
Ps. I'd love to hear about any success you've achieved in the future here.