There's a reasonably simple way, have a look in the SCT folder (not SCTD), there will be a file called SCT_Event_Config.lua
open that with notepad and have a read, the top half explains how to add your own custom messages
Basically what you need to do is find it in the combat log, make a note of what it says and what event was fired (possibly something like CHAT_MSG_SPELL_SELF_HITS, but don't quote me) and follow the examples in that file to write your own event.
I don't have a high enough Lock, else I'd do it for you, but feel free to ask any questions here