Note that you'll need to define clips with a \1 placeholder for the text that will be wrapped by your custom code. For example:
Code:
<span class='x'>\1</span>
BTW, the first 10 clips can also be accessed via keyboard shortcuts. The first clip is assigned via CTRL+ALT+1, the second by CTRL+ALT+2 etc.
These shortcuts can also be changed via
Edit > Preferences > Keyboard Shortcuts.