Relative references between 2 sites on the same Cpanel server.

If the following references work locally within this site,
then in theory, something similar can work between sites.

Goal: .../.../.../home/username/public_html/hello.inc

Verified! ../public_html/hello.inc

Verified! ../../username/public_html/hello.inc

Verified! ../../../home/username/public_html/hello.inc

The following text is such a PHP include of "http://starnectar.com/hello.inc":

Hello!
Hello!
Hello!
Hello!
Hello!
Hello!
Hello!
Hello!
Hello!
Hello!
Hello!