Question: How to force digit sorting on column with class 'abc' in tablesorter plugin.

Question: How to force digit sorting on column with class 'abc' in tablesorter plugin.

I am maintaining a long table with many columns, some of them (specified by CSS class, i.e. 'abc') needed to be sorted by 'digit'. the data in these cell take the following format:

   <td><a href="/path/to/detail?a=1&b=2">1224(<span class="new">30</span>)</a></td>

I've configured tablesorter as follows, this sometimes works well on sorting the above column as 'digit', but not consistent.

$(document).ready(function() {
    .tablesorter({
        textExtraction: 'complex'
    });
    .....
});

Are there some better ways in tablesorter plugin to force some columns (prefer to specify them by a CSS class) to sort by 'digit' order?

Many thanks,
lihao