Hi, if you’re still looking for this (or anyone else), it’s possible in MapPress 2.38.2 and higher. There’s a javascript call you can make to open any POI. Here’s an example to open it by postid (assuming the POIs are linked to posts) for a map named ‘mapp0’:
mapp0.getPoiById(postid).Open();
A ‘template’ file is also available that can be modified to change how the POI list is displayed: “map_poi_list.php” – you can copy it to your theme directory and change it there.