Unfortunately, as I said, I am not familiar with anything to do with Spectrometers, so some of the things you mentioned regarding dark spectrums, etc, did not mean much to me. As for changing up the LabVIEW program, that is definitely doable. The VI you attached appears to be an example program that the manufacturer created to perform much of the functionality of the driver they provided. I do not have any of the subVIs included in the program, but it looks like they are in what is known as a sequence structure (the box that looks like a frame of film). What it does is that it exectues each frame in sequence, one after another, until each frame is complete. I beleive that may be what you mean by the program runs as soon as you click the run arrow.
If you would like for different functionalities to happen at different times that you define, you may be able to use what is known as an event structure. Here is a link to a tutorial on the website that goes over the basics of these structures.
NI Developer Zone: Event-Driven Programming in LabVIEWIf you would like more details, or to open up a one-on-one interaction with an Applications Engineer such as myself, you can generate a service request through our support website at www.ni.com/support. Simply go to that page, and make a selection in the "Option 2" box to either call or email an engineer. This will walk you through the rest of the process.
Have a great day, and good luck with your programming!
John M
Applications Engineer