> Or is it possible to start the external launch config before the ant run?
It is, but you would have to manually launch them, there is no automated way to do this.
There are some options:
You could create a shell script / bat file that performs the command line action / calls ant / performs command line action and call that (the shell script / bat file) as an external tool within Eclipse
As Satyam mentioned you could create a build file that performs the command line actions and include your other build file in that one - that way you don't have to add file system ops to your original build file. See http://ant.apache.org/manual/Tasks/include.html for more info about including build files