External environment refers to the major factors and forces outside the organization that have the potential to significantly affect the performance of an organization. External environment is divided into two parts i.e. mega environment or general environment and specific or task environment.
_tcscat is a C function, to concatenate C-style strings; CString is a class (which has built in concatenation via operator+), not a C-style string.
In C++ it's a reference to a pointer, sort of equivalent to a pointer to pointer in C, so the argument of the function is assignable. As with most data types in C++, you can read it right-to-left and it'll make sense. out is a reference (&) to a pointer (*) to a myStruct object. It must be a reference because you want to change what out points at (in this case, a new myStruct). Like others have said, the & means you're taking a reference to the actual variable into the function as opposed to a copy of it.