How to pass parameters from native to managed

This is from your tutorial on calling a managed class from native code:

If is use COM onterop to call a managed class, I get error  "(80070057): The parameter is incorrect" if the managed class does not define the passed parameters as type string; for example, if a PIC X(1) parameter is passed from native code and the managed class parameter is PIC X(1).
Sometimes I need to pass a number of parameters.  Where can I find the rules for how to pass parameters from native to managed using COM interop?