Where do I start? Which language / track?

In terms of my background I have dabbled with Python, just for fun really, and no particular reason why I chose Python.

I work in education and I want a standard budget sheet (makes it a bit more simple than it is - it has multiple inputs, salary calculations for individual employees, inflation factors, revenue projections, etc. etc. included) that all the schools in my organisation can complete each year and that we can then roll forward and monitor against. I currently have this is Excel and I really want to move away from this as the spreadsheet is slow, version control is a pain, access to from remote locations is not ideal etc etc.

It's almost as if I want to fake Excel on a website.

I have had a trawl around the web and I have seen some software that seems to offer ways of creating an app out of a very simple Excel worksheet. I want to turn something much larger into a website / app. I have struggled to find any advice which I think is a bit odd - I can't be the only finance person to think if only I could turn this Excel financial model into a web app......

Any ideas where I start? Which language should I start with? Which track on Treehouse?

Thanks in advance for any pointers.

Paul