How to set permissions like "For all users" with Sandbox

I wrote:
Do you know how to set this sticky bit in Sandbox? I didnd't found a way to do that.


glsmith wrote: It's not possible in that app.

Mmmh, I see. I think the chmod +t command is sufficient.


I wrote:
Ehm - by the way, how can I add a specific user / group via Terminal?

glsmith wrote:
See my post above. Use the "chgrp" command.


But using more than 2 groups and 1 owner at one isn't applicable with the sticky bit or?

So if I add the group "Sharing" via Finder and type in chgrp staff /test the user who is in the Sharing group can't delete the file but the test user who isn't in the sharing group but in the staff group (standard user) he can delete the file!