I tried doing that with export and set env, but it did not work. how to do it?
~/directory$ export a.home=1 bash: export: `a.home=1': not a valid identifier
The dot is not a valid character in a shell identifier.
So the answer is "you cannot do what you ask":
name A word consisting only of alphanumeric characters and under- scores, and beginning with an alphabetic character or an under- score. Also referred to as an identifier.