Are you talking about using a lettered numbered list instead of bullets? Or are you talking about arranging the text inside the bullets? If the former, I don't think it can be done; if the latter, why would you want that in a bulleted list?
That said, you could "fake it" by creating a two-column table, the first column for the bullets or letters (just apply the paragraph style you want; it should repeat with each new row you create), the second holding the list. You can sort a table ascending or descending by any column you want.
OOo 3.2.0 Portable, Windows 7 Home Premium 64-bit