help with structs and pointers in C++

[ctrlaltcasper]

Ok this is my situation I have this header file:
Code:

struct dir
{
	char name[3];
	int root_dir;
	int has_children;
	int num_children;
	int offset_to_children[2];
	int offset_to_files[16];
};
struct files
{
	char name[5];
	int size;
	int offset_to_beginning;
	int has_fragment;
	int next_fragment;
};
struct fat
{
	int files; 
	int dirs; 
	struct dir *dir_array; 
	struct files *file_array; 
};

In my program if I want to access the struct fat member *dir_array or *file_array, given that this member are pointers to another struct how can I access this members from my main program? This is what I'm doing and it compiles:

fat *pfat;
pfat->dir_array->root_dir=0;

My doubt is if I'm doing it right. Can anybody clarify my doubt and point my to the right direction. Thanks!!!