Something like this should work.
Lua Code:
local f = CreateFrame('frame')
f:SetScript('OnEvent', function(_, _, _, event, _, guid, _, _, _, _, _, _, _, spell)
if event == 'SPELL_CAST_SUCCESS' and spell == 118000 and guid == UnitGUID('player') then
SendChatMessage('rawr')
end
end)
f:RegisterEvent('COMBAT_LOG_EVENT_UNFILTERED')