I could find almost no examples of LabView working with RealSense. There was a suggestion by the makers of LabView about how it might be possible to do so, and a suggestion by Intel employee Anders G that you could do so "fairly easily" by creating a VI wrapper to work with the RealSense DLL file (which sounds like what you are trying to do).
The discussion below talks about how to use LabView with the F200 camera (the direct predecessor of the SR300).
I'm afraid the above information is the most I could find on the subject of LabView and RealSense. I hope that it gives you a useful starting point.
I do not know how to access the raw stream with .c unfortunately. The documented examples cover only C++ and C# / XAML