Creating Links with Attributes

If I drag a file into my topic, it creates a link that looks like <a href="...">.  However, I need my links to have attributes like shape="..." and class="...".Obviously I can switch to the HTML tab and manually add the code, but how do I do it in the Design tab?  In the Styles and Formatting pod, I can create a new style, sure, but there's no category for anchors.  It seems like adding a link with attributes would be a common enough thing, and yet I can find no way to do it other than hand coding, which we're trying to move away from.  Am I missing something?