If I include in CMakeLists.txt lines:

LIST(APPEND CMAKE_C_IMPLICIT_INCLUDE_DIRECTORIES "SomePathToDir")

LIST(APPEND CMAKE_CXX_IMPLICIT_INCLUDE_DIRECTORIES "SomePathToDir")

then i would expect that header C/C++ files inside these directories will be searched for when included in regular .C/.CPP source files for example:

#include "header.h"

and header.h will be in SomePathToDir then VS Code will not complain that file header.h is missing. I know that this requirer integration with C/C++ Microsoft extension.