带有PHP常量的gvim goto文件

I'm using gvim 7.4 and I'm organizing my PHP project using constants like this :

define( 'DIR_HOME', '/');
define( 'DIR_FUNCTIONS', DIR_HOME.'functions/');

Now when I include a file

include( DIR_FUNCTIONS.'functions.php' );

and place my cursor on functions, I would want gv to go to the /functions/functions.php file but gvim is only looking in the current path and I'm getting the following error

Can't find file "functions.php" in path

I could add all the required folders to the path variable but I'm lazy and I don't want to have to do it for every new constant I'll define. Also I'm afraid it won't deal correctly with files having the same name.

Is there a way (a plugin maybe ?) to make all the goto functions recognize and follow the PHP constants ?

I'm using ctags and my constants are correctly followed when I hit <C-]>

I'm sorry if this question was already answered somewhere but after a thorough search I couldn't find any solution

Thanks !