What sort of stuff can you do in VBA?
Run loops in VBA ('underneath' the spreadsheet) to sweep over frequency, numerically integrate, etc.
Move data around on the spreadsheet (copy blocks of data from one place to another)
Change a graph 'on the fly' by using a scroll bar (slider)
Make items appear and disappear (pictures, and other things)
Important resources to help you learn about VBA, and stuff you can download and use.
Three introductory VBA activities