Hi Paul,
It's possible to do something somewhat like this using Job Manager Engine, and inserting tasks into the Application Catalog to handle this. However, if you're looking to get commandline output for the results, I don't think we have anything for this currently.
Now, if you're wanting to do this after building a repackaged project to *.ism format, iscmdbld.exe supports a flag for doing this after a successful build:
http://kb.acresso.com/doc/Helpnet/installshield15helplib/ISCmdBldParam.htm"-m <.cub file name> Use this parameter if you want to validate the installation or merge module package after it is built. Pass the path of the .cub file name with this parameter. "
Now, getting the *.irp into an *.ism is a different story, though. I'll see what I can dig up on this, and post on the other thread.