The character over the letter you're referring to is a breve. Although MS doesn't provide keyboard shortcuts for those, you can still insert characters with them via Insert|Symbol (without the need for the CharisSil font) and you can assign your own keyboard shortcuts for them. You can also create them via their Unicode escape sequences (e.g. 0103, Alt-x creates ă).

Using Insert|Symbol, you will find the characters with breves in the Latin Extended-A character sub-set.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]