Oh, no prob m8
First, add your ball to it's own render layer.
Add your particles to another render layer.
Then, render a pass of just the ball.
Then, in the Hypershade, grab the "Use Background" shader, and apply that to your ball.
Then in the hardware render globals, make sure you have "geometry mask" turned ON.
And also set your hardware render globals to your scenes frame length, and choose an output file type.
(I use tiff or targa)
Also, check that your frame SIZE is correct in there as well.
Then in the hardware render buffer window, runn a pass of your scene, and you will notice that your ball is invisible.
(not really invisible, it just matches the background)
Render out a pass of your particles.
Then in a compositing program like After Effects etc. simply import your ball frames and your particle frames, and layer your particle frames OVER your ball frames.
Most compositors are set up to prompt you if you would like to import your footage that contains an alph channel as:
-Premiltiplied (with color)
-Straight (unmatted)
-Alpha only
-Best guess
..in this case you will want to choose Straight... (I believe)
...sorry, my machine died on me last night, and I won't have Maya for 2 more months untill I can afford a new machine
Israel "Izzy" Long
Motion and Title Design for Broadcast-Film-DS
izzylong.com