Is it possible to add a field to enter and track Comp time?

I would like to add a field (to display on paystubs) to enter and track Comp time.  It would mimic vacation/sick time.

Is this possible?  If so, how do I accomplish this?

Also, I am being asked to track sick and vacation time not accrued (due to reaching max accrual).  Is there a method for this within the system?

Thank you!!