If you want to hide text from Trados 2007 while working in Word, follow these steps:
1) Open you .doc in Word.
2) Go to the Styles section in the Ribbon or Toolbar.
3) Click on the tiny arrow on the lower right corner of the Styles section.
4) Click on the New Style icon.
5) Now create a new style with the following properties (click on the image to zoom)