I just had an idea.
To get a list of all character names who play a server, you could make them start in a room, with no way out other than to walk through a door to get onto the main map or a province. When they walk through the door, us MapQuest to trigger an NPC which loads up from the QuestDiary which then can be used to add the characters name to the name list. Set a flag after it is done so that if they go back in, then back out, it doesn't add them again. Or use the check name list command instead. Just an idea, no idea how it would work though. No clue about QuestDiary or MapQuest :P