This sounds like a very straight forward task.
I have spent many hours developing all sorts of Excel macros, add-ins and custom programs. I've developed form-based Excel timesheets with calendar entries, options for adding new projects, assigning users' time to projects, and summarizing based on year-to-date totals.
I am and expert in Excel and VBA and I would gladly create this timesheet for you.
Cheers,
Grant