[Exim] 2 questions

Hi

I have two questions:

1. How to log lines in routers?

2. How can I do something like have a condition and want to jump to two
different routers dependent on the conditions value.
I would use something like
pass_router = ${if <cond> {routerA}{routerB}}
pass
but pass_router is not expanded..

Thanks,
Steffen