And, obviously, "Byteland" is a sadly lame metaphor for computer sciences

(more like software development, in my case).
Ok people, this is my (basket?) case: I'm an old, old man (41) who wants to go back to his youthful dream of being a scientist, of the natural sciences variety, preferably the physics one. I, in the times of old Númenor, took about 2 years of what you in America would call undergraduate physics, before the so-called "real-world realism" hit my innocent head and I moved to a "real world" career, because scientists die of hunger in the streets, obviously. Well, long story short, bad move. Realism is to follow your hearth. Sappy, yeah, tacky and true.
Back to the elusive, nonfixed point: I have an undergrad Computer Analyst degree from Panama, a Master in networks/programming (from Spain), some coursework in a Computer Science-AI PhD (another Spanish thingy there) and more than 10 years experience as a developer, in three countries. My long-term goal is to get a PhD in Physics, perhaps in climate-change related studies. I know that, at this age, any scientific career will not be...long. But I'm beyond that. I just want to do what I love, so I have no hurries. So, my questions are:
1. Due to $$ issues, I don't think I'll be able (or willing!) to pursue studies in the USA. But Europe is much less expensive and I actually like it there. I'm not aware of an equivalent GRE-like test there, so the question is: if I take the GRE-Phys, would it be about as useful in an Euro U. as an American one? Yes, I know most of you guys are actually American, but perhaps some of you used the GRE to get to an Euro program.
2. Is there any easier way of doing this "transfer" that escapes me? Any input/crazy idea will be appreciated.
Well guys and girls, that's it. Thank a lot, and keep on loving science with all your hearth!