if you are installing agent from epo remotely then you can use the local machine name under the "domain" field when entering your credentials. alternatively you can deploy the epo agent using a script or sending the user a url to click on. once the agent is installed it will show up under lost and found and is fully manageable via epo. epo NEVER cares about domain membership....everything is plain TCP communications back to epo so there is never a concern about domain membership. you just need to get the agent installed.