Start Jetty in rake?

All:
We are going to integrate selenium driven test to our project, it
requires to start the jetty server, we prepare a .bat file, and use sh
to
call it in Rake. then there is a problem, our Rake script blocked in
this
step, since there is no return value from the start jetty task, and the
tasks behind that will never have chance to be processed.

Anyone has idea in handling this?