Add amazon ELB's behind a F5 Loadbalancer

Sorry for the delay.

OK, so in essence (I know next to nothing about AWS and ELB) you are trying to configure Pool Members using a DNS name rather than an IP address? I'm pretty sure that's not possible.

Possibly you could use iCall or iControl to do something interesting here or even a bash script. Not sure what your skills are like in these areas and how you might 'discover' when instances are spun up and down and also what IPs are in use (although the latter should be relatively simple I suppose).