HI we would need more information.
To add a robot to monitoring would require the deployment of a robot and probes.
or updating of a remote probe such as rsp with a new profile to make this work.
To remove permanently a robot would require the opposite of the above PLUS the removal from the database.
if you are talking about temporarily removing it this would involve setting up a maintenance schedule.
I think you would first need to define exactly your scope of what are wanting to monitor.
how it will be monitored
the target systems and probes.
to then look at what could be done.
I know OOTB we do not have support for robot or probe installation using Powershell scripts. we do have third party robot installers packages that could be leveraged with a custom Powershell script but I do not have one.
If you can make your request more specific we might be able to help with a suggestion or pointer in the right direction.