Hide/Unhide columns

I have a spreadsheet that has 28 columns for time entries. Typically only the first 12 columns are used, so I would like to hide the remaining 16 columns (which makes the spreadsheet much more user-friendly). It would probably be nearly impossible to teach all of them how to Unhide the remaining columns (and re-Hide), plus I would like to use the full-screen function when employees enter thier times.

I would like to use a form control in the column heading so that when the employees 'check' it, it will Unhide and then re-Hide the columns.

Any way to do this? Seems like a VB thing to me (out of my league, but would be happy to add one in!).

Thank you,
Ray