XL isn't a word processor - there's no built-in functionality for
automatic hyphenation. XL knows nothing about words, punctuation, etc.

In theory it could be done with event macros, but if you're looking for
hyphenation at syllabic borders, they would have to be rather
sophisticated.

Excel is not a word processing program.

Consequently it is lacking many of the functions of a WP program.

Editing is as simple as hitting F2 and adding/deleting text in the formula bar.

Hyphenation would be more difficult and complex.

Suggest you use Word for editing then copy the results back to Excel if
necessary.

Gord Dibben  MS Excel MVP