How can i make thai search service? by analyzer and external dictionary

using elasticsearch wants to create thai search service.
follow is the requirements.

  1. we must be consist of effective index by stemming.
  2. pre-registered terms of foreign loan words are must be included to the index.
  3. pre-registered terms of stopword dictionary must be excluded from the index.

3. how can i consist 1-3 of these features at elasticsearch?
4. ICU Analyzer is meets all the above requirements?
5. how can i make external dictionary?
( include/exclude words)

Busy, but ask for help .