You said “I want batchpatch to run a script against each machine I’ve loaded into batchpatch and this script will not be executed from within the list of machines.”
I don’t understand what you mean when you say “this script will not be executed from within the list of machines.”
There are two ways that BatchPatch can be used to execute a script against a target computer.
1. BatchPatch can be used to deploy a script to a target computer and have that script run on the target computer. For this you would follow the normal deployment process, but the item that you are deploying is a script, not an installation package. There are numerous examples at Software Deployment. There is also a script being deployed as part of this tutorial: Install Windows Updates Only If Sufficient Space Is Detected On Target C Drive
2. BatchPatch can be used to execute a local script on the BatchPatch computer, but you can feed the target computer name into the script, so that the script can operate against the target computer without actually running directly on the target computer. In this case you use a Local command in BatchPatch with the $computer variable used to send the host name into the script as a parameter. An example of this is illustrated inside the following tutorial: Advanced Script Integration with BatchPatch