Event Calendar 3 -> filter category

i installed “event calendar 3” and this plugin is very good. only thing i miss is to get events filtered by category (events are normal posts in this plugin). i have this in my template:

<li>
            <h2>Events</h2>
			<?php
		    ec3_get_events(
			31,                                      // limit
   			'<a href="%LINK%">%AUTHOR% %TITLE% (%TIME%)</a>',// template_event
   			'%DATE%:',                              // template_day
   			'j F'                                   // date_format
			);
			?>
            </li>

the number “31” for example says that the events of the next 31 days are shown. the main-category for the events is “events”, but i have more events like “music” or “film” they are sub-categories. all i want to do now is filter this out so that i am able to show only the events of the category “film” in a template. i found this:

ec3_get_events(limit,"3,4"); (https://penguin.firetree.net/pipermail/eventcalendar/2007-October/002583.html) but it won’t work … :-/

any idea