I'm not sure what you mean. I would have expected that you would pre-define input and output names corresponding to the inputs and outputs available on the PLC (X1, X2, Y1, Y2, etc.). The interpreter would parse the file, and identify what addresses correspond to those "magic" I/O names, and connect those to the physical inputs and outputs.

Then you can either use those directly in the program, or use an internal relay in the program and connect it to the appropriate in/out using a single rung with contacts and a coil.

You can likewise create "magic" integer variables for ADCs or DACs or whatever.