Custom app "view" that really just spits a result out to Home?

[Dave Britten]

I'm tinkering with a custom app to do some time-based regressions. It's based on Stat 2, and it'll have a few customized views:

Symb = input form for logging data point
Symb Setup = configure some other details of the case (target value, regression model, etc.)
Plot = graphical representation of the data + regression line

I'd like to have the Num key switch back to the Home screen and perform a calculation that's displayed in the history (probably just a function within the app named Calc() or something). Is that something that can be done?