Out of curiosity, why do you need to use Nonlinear instead of Parametric Survival? If you are fitting a Lognormal survival model, the Parametric Survival personality of Fit Model should be able to fit the model and give you the profilers you're looking for.
Parametric Survival in JMP can handle the Weibull, Lognormal, Exponential, Frechet, or Loglogistic distributions.
-Michael
Michael Crotty
Principal Statistical Writer
Manager, Statistical Documentation
JMP Development