userinclude directory-list
Use the userinclude statement to define directories to be scanned for files specified in #include statements in source and resource files.
It may be specified any number of times, and each may have any number of directories.
When a project is being built, the pre-processor will be invoked specifying all the userinclude and systeminclude directories indicated in these statements. No standard include directories will be searched unless the project links to Win32 libraries under WINS.
Files included from source code with a line such as
#include "squash.h"
will first be searched for in the directory containing the source file, then in the userinclude directories and finally in the systeminclude directories.