HP-UX How to remove file permissions depending on their directories

[EvgenyFF]

have a common directory shared by ftp

for example "share" directory
have about 400 Ftp users
the challenge is to
1) each user has the right to write to the directory file, and users can only delete owner's files
2) Administrators ftp - has full access (there will be a few) 

3) for example a directory with 777 permissions (chmod) 

and files inside if put chmod 000 may remove anybody. 
how to get around this?

1) don't now, tryed different ways - Sticky bit, ACL and the group change, their shorter did not work for me. How can i organize this scheme?

2) this i understand, i can do it by setacl

[Dennis Handly]

The sticky bit will solve 1).

2) Your ftp admins must be root to have all access.

umask can be used to remove all but owner permission to read? or write files.