Programmatically retrieve team area by user Id

Hi all,
I try to retrieve team area by work item creator userId for populate a new custom field.

I will use this new information to create a simple query that show me all defects opened by team area.

I try in this way but I hope that exist other simple way:

IContributorHandle creHandle = wi.getCreator();

IContributor creator = (IContributor)(repositoryItemService.fetchItem(creHandle, null));



List<ITeamAreaHandle> teamAreas = projectArea.getTeamAreas();

for (ITeamAreaHandle taHandle:teamAreas) {

	ITeamArea ta = (ITeamArea) (repositoryItemService.fetchItem(taHandle, null));



	IContributorHandle[] members = ta.getMembers();		

        for (IContributorHandle memberHandle : members) {

		IContributor member = (IContributor) (repositoryItemService.fetchItem(memberHandle, null));

		if ( member.getUserId() == creator.getUserId() ) {

				//TODO add this value in custom field

			}

		}

}

Moreover, the task have the Creator UserId value when it's just open or the creator is valorized only after a save action?

Thanks
Andrea

ps. I use RTC 2.0.0.2