Use the Superscript feature. If you use them a lot, you can add the icons to a toolbar. To do so, use the following:
To add Superscript or Subscript to the toolbar area
1.. Right-click in the toolbar area
2.. Select Customize from the pop-up menu
3.. Click the Commands tab
4.. Click the Format category on the left
5.. Scroll down and find the Superscript and Subscript commands
6.. Drag each icon to an existing toolbar (I put them next to the "B", "I", "U" commands)
Now all you need to do is click the icon to turn it on, type your "power", click it again to turn it off, then continue typing.