Forums / Cotonti / Skins / Theme help

i was looking through the code and found where are they created.
I have a question.
If i go to functions.php(line 1553), add a hook like "$extp = sed_getextplugins('stars.tags')" right in front of it,and in the plugin do something like this :

return '<img src="skins/'.$skin.'/img/system/stars'.(floor($level/10)+1).'(PHP.usr.theme).gif" alt="" />';

will it work,and are such things allowed in the skin contest?