Outlining in Word is, in general, frustrating and should be rethought out. But until that happens, I have an example from a linguistics notation known as interlinear glossing. (It's in the Mohawk language if you're wondering.)
The standard format has numbers subdivided into letters. The number is sometimes in its own line followed by the language in question, but I also need to know how to put the number and letter together ("(1) a"). The distance between the letter and the text after it is not important. It just needs a space. I'll handle the internal word-element alignment with tab stops.
I'm thinking there is a way in word to define custom outline formats that I can reuse.