To locate the actual coordinates of this cache, you will need to complete all five stages of the "Ice Cream, Creemee or Soft Serve...Dish or Cone" Adventure Lab. The "start" is located in West Lebanon. (N 043 37.355 W 072 19.634) However, the Adventure Lab can be completed in any order, so you're welcome to start in Quechee, Enfield, Lebanon, West Lebanon or Plainfield.
To find the bonus cache location, you will need to fill in the coordinates as follows:
N 043 AB.4D0 W 072 1E. AAC