Need help with this

[WALP]

my guess is that what you want to do to fill the area of a mesh with particles, at least thats my guess. in that case you proberly wont be able to do that, it would only be possible if the particle editor allows importing a mesh to guide the particles but i dont think thats possible.
alternatily you could use a texture with transparency that looked like particles and animate it in the material editor. But i dont have the time to test this so i cant really say if it would work. hope it works out for you but i doubt it.