Help on Project

Hi Everyone…I am working on a project regarding a mobile dvr. During a triggered event, my mdvr has an output of 200ma to trigger a relay. I need to know how to take that 200ma and trigger a relay to provide 12v to a siren or safety light. If possible, once the timed alarm stops and no 200ma is present to trigger that relay any longer then the light or siren will stop. I need the light or siren to continue until I turn it off or reset it, not the mdvr supplying the 200ma. Is this possible? Also the mdvr has wifi. If that same trigger from the mdvr could trigger a way to send a text message or email that would be even better and preferred. I thank everyone in advance for your help!!!

Dale