.rar hidden file

I need a way to hide a keyfile (Which means I can't change the data on this "Text file" at all) inside of an image. Which I then convert to a .rar and open to acess the text file. Anyone can help?

?

google steganography
you probably want to hide data in a 24-bit color gif

oh, if you are talking about the RENAME TO RAR AND OPEN trick, do this from a win cmd prompt:

copy image_file.jpg /b + rar_file.rar /b newfile.rar

do this from a unix bash prompt:

cat image_file.jpg > newfile.rar; cat rar_file.rar >> newfile.rar