IVR / Dialogic library

Question

I'm developing an Interactive Voice Responce system that works accross a Dialogic D/4PCI board. I downloaded the system release drivers from Intel, but there doesn't seem to be a library that will enable me to develop the system in C#. (Their samples are all in C, and converting them to C++ gave endless errors) I have found some relevant libraries (dll's) online, but they cost quite a bit of money and I would obviously prefer something free. There is a service running on the machine called 'Dialogic'. Could I access the board's functionality through this? Any information about accessing the hardware through C# would also help. I know this might be an obscure request, but any pointers will be greatly appreciated.