Need to take D drive backup

Dear all

     I am taking daily  Manual backup of D drive contents which includes hidden folders & normal folders,

     Where hidden folders are confidential and only the respective users should see the folders and others should not.

     But in my scenario we are 4 members who are all having administrator privileges, So i want to restrict the 3 of them

     to access all the contents in D drive also they should do manual full backup everyday morning.

     I dont know what kind of user i need to create, and what kind of members they should have and also they need to take

    backup of the D drive contents, where they should not get in to any folders (hidden & normal folders). kindly help to resolve this issue.

M.chandrasekar