Hi,
Just to add to Dennis' comments, it would appear that you just need to setup a finite acquisition with the rate, samples to read etc. setup to suit your requirements. This will in effect give you an array of data which you can then use as you will, such as aligning with other data for correlation etc.
As an example as to why you shouldn't try this using software timing under Windows, should someone start moving the mouse around, opening another application etc. this could effect the loop timing as Windows always has overall priority. Using the hardware timing of your DAQ device would avoid this.