To illustrate how such a function that might look

tclrepl > puts [ngspice::get_net_for_path {m20.q}]
"net123"
tclrepl > puts [ngspice::get_net_for_path {m19.s}]
"net123"
tclrepl > puts [ngspice::get_net_for_path {net123}]
"net123"

This would look at the netlist graph and take any path connected and resolve it to the net