Passing a string into Crystal Reports - how?

I`m using Crystal Reports 8 - developers edition.

How do i pass a string into the report from Visual Basic (6, sp4). I`m using the RDC, not the old .ocx.
I`ve played around with parameter fields, but i`m not sure this is the right approach.

Typically, the help provided is useless.

Its a simple question, any ideas?

Thanks,
Alex.