Using excel to track vacation/sick accruals and time taken

Is it possible to use excel to track Vacation/Sick accrued hours as well as Time Off?

Looking to set this up:Policy.JPG

I'd like to set it up where each time I open excel it would run the accruals based on the employees start date, or click a button where it would update. I'd also like to lock in the formulas once set up so that there isn't any accidental changes.

Is it possible, and how difficult would it be to set up and maintain? I'm no pro at excel, but I do know how to get around and do a fair amount of functions. My company currently uses MyBiz, but the program is old and unstable so we are needing to move forward, but MyBiz wants annual fees for the program to work, and since I only use a tiny portion of their product to just track accruals and time off, it's not worth the money. I did find another program called Staff Files that looks like it will work and alot less expensive, but it got me to thinking if this can be done in excel.

Thanks for your help in advance! I very much appreciate it!
Jessica