If it is possible, should be pretty basic, but I am puzzled how to ask Google the right question (or it is impossible).
Lets say we have
/home/user/
...conf
/home/user/candidate/
...conf
We have homedir and some subdir.. programs will use naturally from homedir(*/home/user*)
What I need is to temporarily change home user to */home/user/candidate*, so programs will call */home/user/candidate/conf*, instead */home/user/conf*
Now, I don't need usermod or anything else to change permanently /etc/passwd, i want to temporarily force programs to use my directory, thinking it is home, but on reboot fetch */home/user* and act normal.
Using */home/user/candidate* as home only session long, no usermod stuff.