If it is helpfull, you can also add a dummy device to your circuit like a 0V DC source, or negligible resistor.
Some time ago I have worked on PSPICE 9 on defining custoim functions (like the current comparator you mention). I can search on my files (will take some time) If it seems helpful for you.
I need to know inductor current so I can control my actively clamped resonant inverter.
I know what is voltage and current probes and I don't care about current value.
I need to compare it with reference current in order to drive transistors.