If you want to create a header file, you just write the required header file at the turbo c (or even at note pad), then you save it as *.h file .When you want to use it at your program, you just add :
#include "E:/myLibrary.h" //where E:/ is where you saved your library and myLibrary.h is your library's name .
Note that you should use quotations (" ") instead of < > and must specify the complete path for the library .