I'm a student trying to create a Word template displaying comments on the left side of the page on even page number and on the right side on odd page number. I don't know if this is possible.
On the Layout tab, click the dialog box launcher in the lower-right corner of the Page Setup group. In the Page Setup dialog box, under Pages, in the Multiple pages field, select Mirror margins. Under Margins, you'll then probably also want to increase the Outside value, to give your comments more room.
In the Styles gallery on the Home tab, or in the Styles pane if you have that open, right-click whatever style you're using for your comments, and then click Modify. In the Modify Style dialog box, on the Format drop-down menu in the lower-left corner, click Frame. Under Text wrapping, Around should be selected automatically. Under Size, set the width that you want your comments to have within the outside margin that you set earlier. Under Horizontal, set the Position field to Outside, and the Relative field to Page. You'll probably also want to set a Distance from text value, so that your body text doesn't get too close to your comment text.
That's it. Here's an example.