Way to update custom properties via a script

Hi,

Does anyone know how to update an agent's custom properties via a script or the command line?  We use our RMM package to install the agent, and it sets some custom property fields to match information in the RMM package.   In our use case, the information may change over time, and we currently need to manually update the custom properties to match the RMM package.   Would like the RMM package to send periodic updates that keep the custom properties in SC/Control current, but I have not found a way to do so.

Thanks in advance,

Alex