Can I stop arbitrary processes (or wait until they finish) during a BuildMaster deploy?

Is there a way to terminate an arbitrary executable as part of a deployment step? Our product will kick off long-running executables in the background. If we deploy while those are still running, the deploy will fail; however, these are not typical IIS or Windows Service processes. Is there a way to terminate arbitrary processes, or a way to wait until those processes finish execution? Right now we only see one option: manually ensuring those executables are not running on the target deployment machine.

Yes, this can be done with an Execute PowerShell Script action: http://technet.microsoft.com/en-us/library/ee177004.aspx