Crystal reports parameretes VC++ ICRReport

I use CR with Visual C++ 6.0 and I don't use CR Active X viewer because it does not export correct the reports.
Instead, I access the reports preview using "cpeaut32.h" (ICRApplication, ICRReport, ICRView etc.).
I need to pass some parameters at runtime to the report, but I couldn't find a way. There is a an interface ICRParameterFieldDefinition but i couldn't figure how to use it.
It would be very helpful an advice or example about how can I can do this.