Plz help,
I have declared three stuct

struct student
{
    CString Struct_Name;
    CString Struct_RollNo;
};

struct Division_struct
{
    CString strDivName;
    CArray <student, student>arrStud ;
};

struct Class_struct
{
    CString strClassName;
    CArray <Division_struct, Division_struct > arrDiv ;
};
///to access class struct
   CArray <Class_struct,Class_struct> arrClass ;

My question is how to add new entries plz help

What are CArray and CString?

To set a member of a struct, you first have to instantiate it:

student myStudent;

Then you just use a '.' :

myStudent.Struct_Name = "David";