Custom user/group properties

Hi,

Is there a possibility to extend the standard user/group properties (CQ5 Security)? I would like to add some more properties then the standard name, mail, about,....

I've tried to extend the dialog by cutomizing the UserProperties.js Dialog. The Problem is that cq5 doesent save the newly added propertes. There is a save function using the folowing service.

                url = CQ.HTTP.externalize("/bin/security/authorizables/POST");

                url = CQ.HTTP.addParameter(url, "Authorizable", frm.findField("id").getValue());

It posts the parameter but it doesent get saved.

Is there a way to make it work?