What I would do (and did just to make sure it could be done) is to use the GetRegistryInfo Control Module to configure MSP to pull the value you want from the desired Registry Value into an MSP Device Attribute.  Then use a Dynamic Registry Settings Object to deploy the value from that MSP Device Attribute to the desired location in the Registry,  It is kind of a convoluted way to achieve something that could be done with half a page of code, but doing it the way I suggest can be done without writing any code. For convenience, I have attached the CSV files for two Settings Objects that worked for me.  Note that the Settings Object defined by GetRelayServerIpAddr.csv won't work unless/unilt GetRegistryInfo.apf is deployed.  Note also that the Settings Object defined by SetRelayServerIpAddr.csv will only work with a suitably recent version of MSP Agent.