First of all, save the replay. Then forward it to either:
Option 1:
Bear in mind that once a player's alleged malpractice has been forwarded by you direct to enforcement@relic.com, it is up to Relic Entertainment to decide whether your report was correct - and what punishment is most appropriate. We have no influence on the final decision.
Option 2:
https://www.coh2.org/user/6242/sturmpanther