You can easily add a variety of different styles of line under sections of text on your page using the underline option. You can place a couple of different styles of line through the middle of your text using the strikethrough option. Word doesn't provide an equivalent to these though for adding a line above the text.
The Word help facility doesn't help much with working this out either since it directs you to the borders and shading option where you can successfully add a line above your text but only if you want it to go across the whole page. The only thing you can set up with this option for a selected section of text is to place a box right around it. If you try to turn off the sides you don't want then the whole box turns off, not just the side you selected.
The only way I have found to set a line over specific text that will stay with that text and isn't just underlining the text on the line above (assuming that there's anything there to underline) is to create a table to hold the text that you want the line over. You can then set the top border of the table to display the line in whatever style you want.
This article written by Stephen Chapman, Felgall Pty Ltd.