This plugin (or add-in, as Word 2007 has it called), will conveniently allow to to insert Quranic verses and the translation of your choice. In English, there are two types of translations to choose from, one from Yusuf Ali, another from Muhsin Khan.
There are also French, German, Spanish, Malay, and many more translation available. Works with MS Word 2000 and higher. Tested on Word 2003 and 2007.