Generic command line task does support running against the servers you chose. However the script/application will need to support remote interface i.e., it should accept IPaddress and credentials (optional) as parameters and run the commands against that IP address.
The generic command line task runs on the OME server and does not run on the client systems. For your example above, you will probably need SSH based script/application that accepts IP address as a parameter. At run time, the script has to make a SSH connection to the client systems, run the command locally on the client system to get the desired output and bring the output to the OME server.
To choose servers, use $IP in the Arguments field. This will force "Targets" tab to appear automatically for selecting the targets.