The easiest way is to create a text box with the words in, (Word 2003 - Copy and Paste it outside of the Drawing Canvas), then

Select the box and right-click > Format Text Box > Layout (tab) > Advanced > Picture Position (tab) > for both H & V Allignment, you need to select Centre Relative to: Page

If you do this once, then recopy the Text Box, you should be able to go to the next blank page and paste and it'll go to the correct position on the page!