User App to Track Diving Mileage, Gas, ect.

I was wondering if there is an application I can run on my Empeg that would allow me to track mileage and gas receipts?

I only need the data in a simple comma delimited format that I could import into Excel or something. What I want to be able to do, is when I get in the car (when the Empeg boots up in car mode), have it ask me the current mileage. It would of course, know the mileage from the last time I imputed it. Then, I would want to select from a list of things like "Business Mileage", "Personal Mileage", or maybe some simple configurable list of what I'm doing. The next time I start the Empeg and input the beginning mileage, it would "complete" the last trip (because I'd be starting a new entry) and I'd be able to calculate the miles. Begin able to track gas purchases (# of gallons [or liters for you euro folks]) and price paid would also kick ass, but it secondary to my desire to track mileage.

Is anyone doing this? Is there an app I can run that is similar and simple? Is there a scriptable adding for the Empeg that would allow me to design my own app and interface the Empeg or Hijack menu?

I'm sorry if I'm sounding like a newb, but I don't now a whole lot about user apps... the most extreme thing I've done to my Empeg is install Hijack!

Even better, make it GPS functional. I would think that's possible.