The dialog for Edit Plot Expression is a subset of the Plot Vector dialog where all vectors to be plotted are specified manually. (This dialog exists for historical reasons.) After typing in the expression you wish to plot, click OK.
Examples:
dc?.id(m1) Plot the DC drain current through the ML MOSFET for all DC analyses.
tran?.v(2) Plot the voltage on node 2 for all transient analyses.
sp1.tran.v(3,2) Plot the transient voltage difference between nodes 3 and 2 for analyses in the analysis group SP1.
NOTE: You can use a (?) to replace a run number. This will match all runs.