Objects id

I've been searching through the forum and haven't been able to find the answer to my question. I'm using an initcontainerradiussearch (in c++) and the return type on containersearchnext is an object ID. I'm not sure how to use that. How would I get the actual object from the server id? I would like to be able to get the actual position of the object for tracking purposes. I can get the distance, but I want the actual object...I'm trying to get projectile tracking working. So everytick I need to know where my target object is, so how do I get the object from the id? Hope that makes sense.