I don't know if this is what you were looking for, but I got an answer:

42^2 + 12^2 + 10^2 = 2008

I started by squaring 45 and then moving back from there with 44, 43 and so on. I then subtracted this squared value from 2008. When I got to 42^2, which equals 1764, I subtracted it from 2008 and got 244.

244 = 144 + 100

244 = 12^2 + 10^2

I then added these two squares to 42^2 and got 2008.