Some of our alters have things that belong to them. they are just small things, sure, but they are THEIR things.
Have you talked to other members of your system about how you feel? When we talk to each other and listen to each other we are able to work together much more effectively. Part of working together for us is looking out for each other too. We do our best (our best isn't always very good, but its a work in progress) to find ways to get individual needs met.
Ultimately all individual needs are also a need for the whole.
I don't know what kinds of things you want to belong to you, but. Well, I'm just saying, I don't think it's impossible.