Hi,
You either use a binary file or a hexadecimal file representing every byte of the binary file.
Language has nothing to do with it - the code burned into the controller is Machine Code.
Just find out if the programmer you are planning to use wants a binary file or a hex file (most professional programmers use binary files as the default, but can be changed to hex file (beware of the many different hex file formats - Intel hex is one of the most widely used).