I wouldn't advise using lists, ordered or unordered, styling options are limited in ePub2 and support is sloppy.
It might be possible to use some combination of left margin for the titles, and relative positioning for the numbers (maybe with width:0 or display:inline-block). But it seems alignment is wrong. This works in the browser, though, and doesn't use non-ePub2 CSS:
https://jsfiddle.net/jm2j8kmn/