Well, it depends on what induced the overrides. I've found that, as Word and InDesign have respectively expanded their multilingual capabilities, that it's possible to define stuff in your Word files that CS2 ignored, that later versions won't. Like, for example, whether or not OpenType methods are used when determining diacritical distance from base glyphs in Arabic.
So your only choices are to either a) groom your Word styles really carefully, figuring out some way to remove the information that is causing the override, or b) finding a better method to clear the overrides. A) may require some VBA scripting ability, or other in-depth Word knowledge. B), however, can be really easy if your entire document is one long text flow. My workflow often features "select all, whack keyboard shortcut for Clear All Overrides." I assigned an easy shortcut because I Clear All Overrides all the time. There are other solutions out there - I recall seeing a clear-all-overrides script recently, for cases where the user doesn't necessarily thread every single text box without fail.