Distributed application architecture question

I am struggling with an application architecture problem that I hope somebody will be able to help me with.

I have a number of control systems each connected to the serial port of a number of PCs. Some PCs have more than one system connected to them.
To keep it simple, let's assume

System#1 is connected to serial port#1 of PC#1
System#2 is connected to serial port#1 of PC#2
System#3 is connected to serial port#2 of PC#2

I have to write a general purpose communications application (has no user interface) that runs on the PC connected to the system.
Ideally, for the example above, I would have two instances of the communications application running on PC#2.
This application has to receive comands from and return system data to another, general purpose monitoring, application (with user interface) running on, lets say PC#3.
One of the commands to the communications application would be "Connect to the system attached to serial port x"

Because this is a DCOM application, I am thinking ActiveX.exe for the communications application.

The root of my question is :
Is it possible to uniquely reference an instance of a DCOM application having the same name as other instances of the similarly named application which may be running on the same or another networked PC?

If the answer to the question is NO, any suggestions for an architecture that would work?

Any help would be appreciated.