Translation workflows involving both Word and InDesign have to be carefully managed from the beginning, or flowing the translated text back into the source InDesign document becomes both time-consuming and error-prone. The tendency towards delays and errors is accentuated when the person doing the formatting is not literate in the target language.
You could always File -> Place your Word document. I don't know if that will help you or not, because I don't know how your InDesign file was built, but it might be faster than copying and pasting. If your text frames aren't threaded into stories, copying and pasting might be faster in the end.
If you tell us more about what you're trying to do, we might be able to come up with more specific suggestions.