It sounds like what your describing would lend itself to a dialog function. Where you would create a dialog to accept your inputs and display your answers. the dialog programming and formulas would be on a hidden page and would handle all the inputs and outputs and display them within the dialog as well as post them to their proper cells.
It's been a few years since I've used them, (or even a spread sheet for that matter) and I use Open Office rather than Excel, so my terms may not quite match Excel's. but I'm sure Excel has something similar.
I cut it twice, and it's still too short!