I'm not sure of what particular instrument driver you are talking about, but you should be able to create the dll quite easily in VC++ provided that all of the libraries referenced in the source for the driver are freely available via installation of the NI-488.2 and NI-VISA drivers (as well as the IVI driver creation libraries if the driver has this design spec). If the driver requires any special libraries that only come with CVI you will need to purchase a license for CVI in order to obtain them, which at that point you might as well use CVI to build the dll.
Now, for instructions on the conventions used in building dlls that are accessed in LabView you should take a look at the "Using External Code in LabView" manual (lvexcode.pdf installed with LabView), which
goes into great detail about all of the considerations you need to make. One thing to note about this though, is that I wouldn't try using the "Convert CVI Instrument Driver" tool in LabView with this dll that you are making in VC++, there are all kinds of pitfalls that you can run into without having any access to CVI. So you should really just try creating the dll to get access to the functionality the source provides, and then use the Call Library function vi for each function in LabView yourself.
Jason F.
Applications Engineer
National Instruments
www.ni.com/ask
