I Need Help !

I have a very important question , and i think it's not important for me only

I have a Host { Domain } with Only 1 FTP user

and i will use it , as all my Company Bracnhes will use it

which means that more than 7 will use 1 FTP user , and it's the main user , because it's the only one

i want to make something like password or something like that CODE whatever

which denie any Delete Permission , so no one can delete other works

plz write to me what i can do but fast .. thx

and how is that ? tell me the exact way

tell me how to do it plz