You can use NJ Transit's "Trip Planner" to see routes from JC to Fort Lee.
New Jersey Transit - Home
It looks like you'd have to take at least two buses.
When we lived up in that area I took the jitneys a lot & never had any problem. That being said, the jitneys are not regulated like NJ Transit.
One idea is to take the Light Rail to Port Imperial Light Rail Station & then take the NJ Transit 158 bus to Fort Lee.