Hi Tom4111,
To create a DLL of a VI or set of VIs from LabVIEW (to be used by other environments), you will need to use the Application Builder by going to Tools->Build Application or Shared Library. If you do not have this option (only comes with LV Professional & DevSuite), the Application Builder is available for purchase separately.
Also, read this post if you're interested in making a llb into a DLL:
http://forums.ni.com/ni/board/message?board.id=170&message.id=106555&requireLogin=False
Note: LabVIEW can use already created .NET assemblies. However, currently LabVIEW cannot generate .NET assemblies to be used in .NET. The Application Builder will only generate standard DLLs (VB6 style DLLs).
Hope this helps!
Travis H.
National Instruments
Travis H.
LabVIEW R&D
National Instruments