Make your emitter directional and then mess with the directional spread to get the particles going in the direction you would like.
As to not getting duplicates. If you set them to come out sequentially, you should be okay. Just set your particles per second to be your number of icons multiplied by the frames per second of your comp divided by the number of frames you would like them to be emitting. That might work.
- The Great Szalam
(The 'Great' stands for 'Not So Great, in fact, Extremely Humble')
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