How To: Show Triplet notation in Text Entry mode using special characters

I'm entering some music that, on the original score shows staff text for direction on style. It shows that beamed eighth-notes should be treated as a triplet with a quarter-note and eighth-note (I've attached a small screen shot).

I can see, in the special characters dialog, what would seem to be all the necessary things, but there must be some trick to entering these to get a properly bracketed tuplet as special-character text that I'm missing.

Any advice?