Split Surface by Named Point

I would like to split a surface with an isocurve through a named point. It appears that you are not able to script geometry selection for this scenario (say, using SelName or SelPt). The same for ExtractIsoCurve.

The selection “works” but the result doesn’t seem to be passed to the split command so nothing happens. So the following doesn’t do anything.

-selsrf
-split Isocurve -selname MyPt enter

Anyone have ideas for how to accomplish this?