Darshan,
What 'opc_remote' file are you referring to? PCo does not maintain any file like that, and neither does Kepware to my knowledge.
In order to connect to a remote Kepware instance using OPC DA Agent you have to peform DCOM configuration on PCo and Kepware servers to enable connectivity. Please refere to the Kewpare DCOM configuration document for guidance.
You can configure multiple PCo OPC Source Agents and each can connect to the same or different OPC Server, but on only One Agent can be referenced in an Agent Instance.
Also, recommend you upgrade Kepware to V5; your version is very old and may no longer be supported by Kepware.
Regards, Steve