Having the history of the question
The relevant lines are
    labelString = oCurs.ListLabelString
    oCurs.getText().insertString(oCurs, labelString & " ", False)
I’d like to insert labelString as a formatted string with char style ZZZ.
In HTML-ish, that would be equivalent to
 <p><span class="ZZZ">'content of labelString'</span> ... </p>