Dynamically get parameters names of a Step Type

Hello everybody,

I am coding the ProcessModelPreStep in order to have access to each step of the running sequence, before it has been execute. With the following expression I access to the type name of the step:

Locals.Type_Name = RunState.Caller.Step.StepType

But I can't find the expression to get access to all the parameter names of the step type.

Does somebody know such an expression to do that ?

Thanks you !