Need help applying 'v5' option of linmod to the linearize command.

I've got a complicated nonlinear Simulink model. I can generated a linearized state space model with linmodv5 if I have input/output ports at root level. I'd like to do this programatically at various locations in the model, so I've tried the linearize command, but this gives me empty models. I assume this has to do with the different algorithms used. I've tried different options, but to no avail. Is there a way to apply the linmodv5 algorithm to the linearize command?

Thanks,

-mcd