I'm sorry know one helped you with your question...yes it's the same as petit computer! But the circle pad is a lot harder than a simple (if B==16 then so and so) same with the C-stick..that is if you have the new 3DS.
If you need help with anything just ask me. ;)
To use the circle pad, you need to use the fallowing code (x=50:y=50
Sp=2
Wile 1
Vsync 1
Spofs 0,x,y
Stick out sx,sy
Y=max(min(y+sx*Sp, 384),0)
Y=max (min(y-sy*Sp, 224),0)
And that's how you set,and move a sprite with your circle pad!