If I'm understanding you correctly....
You could edit your HOSTS file and map a URL specific to your scheduled tasks instance. For example, in your HOSTS file an entry like:
# Map scheduled tasks URL to Instance 1
Where the IP address is the specific instance for your tasks and should bypass your load balancer.
Thanks for the reply, but I was referring to Application Server level load balancing, not the physical load balancer in front of the physical servers. Calling localhost effectively does what you propose, taking the physical LB out of the equation. I was looking for a way to isolate the specific instance when running CF with multiple instances configured in a CF cluster.