I suggest you change your question or edit this one to better fit what you want. I can see as you asking two things:
1) Generate the particles itself. where you can use the Particles or Particles2D node and add it to the scene and remove as you want.
2) Detect where the mouse is in the scene so you can set your particles scene, from above, to the correct place. Simple on 2d, i think you can get it from the mouse click event, on 3d you have to also discover where the mouse was pointing in the envionment.