All of the stress symbols are available in Word; it's just a matter of choosing a font that supports them and knowing which characters they are. See:
http://en.wikipedia.org/wiki/Systems...ode_characters
You'll find these symbols in the Cardo and Segoe UI Symbol font sets. To use these symbols, simply type the numbers after the '+', then Alt-x.
For accenting particular characters, you can also look in the 'latin-1' extended and supplement sub-sets, as well as in the spacing modifier and combining diacritical sub-sets (again, these are font-dependent, and can be found in standard fonts like Times & Arial)