Adding a Comment to a user in ML Server

With the old WGM we could add a comment to a user, it made it real easy to sort users. Ex: I would give all the sixth graders the comment 2016 which is their 8th grade graduating year) When I was ready to delete them as 8th graders, I could sort by comment, put in 2016 and all the now 8th graders would appear, I could select all and delete. Made it real easy.

In Lion server (actually ML server but didn't see a discussion for it) I cannot find where to do that. I realize I can get the WGM and use it but they talk about it being legacy software and was hoping to achieve the same with just ML server.

Is there a better way to manage this sort of sort? I can't even get the filter users option to do much of anything.

thanks in advance