Nevermind, I found a free way to do it. Here's How.
Download and install
this DLL File installer from
http://www.mnwright.btinternet.co.uk/graphix.htm
Download and install
Show image converter from the same location.
Make your image in whatever graphics program you want and save it as a standard 24bit or 32 bit bmp then open it in Show image converter and save it as "WindowsNT 16 bit bitmap (565)"
and you are done.
Note: Make sure your image is 24 bit or 32 bit before opening it in Show otherwise you might not see the "WindowsNT 16 bit bitmap (565)" option in the dropdown box.