Login as priviliged user. Then change the permissions of '/httpdoc/d' in a way that PHP cant access it anymore.
The commandline for that could simply look like this:
chmod 700 -R /httpdoc/d
With that, only the owner of this folder can use it and all of its subfiles and subfolders. (If the user under wich PHP is running - typically 'www-data' or 'apache' - is the owner of this folder, you have to change the folder owner)
When you have done this, turn off the error reporting.
For example:
@include "/httpdoc/a.php"
(There are other ways for doing so as well. E.g. error_reporting())
Regarding your comment:
There is any way to do this from script in PHP and only for this script? I want to allow including only from selected directory dynamically. Other scripts should be able to include all files so changes should be local.
If u have files like "/httpdoc/a.php" u dont 100% trust in, do the following.
Put them in a separate directory. You can put all other files except your secret ones (/http/d/e.php) in there as well.
Configure that directory as described here:
PHP - a different open_basedir per each virtual host