First you need a programming language. There is a huge variety ranging from easy but very slow (VB, Java) to hard but extremely fast (ASM, C/C++) and everywhere in-between. Just do a search on Google for programming, and you?ll find loads of information to help you pick and learn a language.
Next you will need to actually learn that language. Depending on your experience and which language you choose, that can take anywhere between a day (if you have a lot of experience) to several years (if you know no experience). This is going to be the hard part if you don?t already know how to program!
Once you are very comfortable with programming in your language of choice, you will need to get experience with the more advanced parts of your language, such as GUI and graphic APIs. This, again, can take days or months, depending on the language and your learning ability.
Then you?ll need the file formats:
http://uo.stratics.com/heptazane/fileformats.shtml
After that, if you don?t know what to do, nobody can help you.
Any more specific questions?