[Question] Is there way to set particle emitter on certain place?

I'm doing some testing of environment effects implementation for PA using current effect system, e.g some early work on snow:
https://forums.uberent.com/threads/weather-environment-effects.51468/#post-788802
I'm already managed to make it looks good, but main problem that I'm need to use some unit for this, so I'm need some way to create particle emitter somewhere in atmosphere.

I already know that I can use north and south pole for it, but there is two problems with them:

1. N and S letters have transparency/blur effect which seems to be hardcoded.
   If I move camera near to position of symbol snow looks more like a steam and effect also work different in free camera mode. Is there way to disable it?
2. Other problem is position of those symbols, it's also probably hardcoded, am I wrong?

Any ideas how can I create particle emitter where I like (e.g in volcanic crater)?

Bonus screenshot:

awesome!

let it snow let it snow let it snow!