Grouping images for Focus Stacking.

When out shooting macro I can end up with 50 or more sets of images to be stacked. 
The easiest way I find to pass them onto Helicon Focus (the focus stacking software I use) is to end up with a set of subfolders each containing a group of images to be stacked. It is then easy to use the batch process function in Helicon Focus to select these folders to process them.
The images to be grouped are shot in a burst so will have a small delta time between each shot.
I see FastRawViewer actually uses the mS field of the capture time (great). What I would love to be able to do in FastRawViewer is select a group of images and move them into subfolders, moving on to the next sub folder based on the delta time being over a given threshold.  (and be able to provide subfolder name prefix with increasing number)
 
Have I missed such a feature or does any one who does focus stacking found an alternative way to achieve an efficient way to achieve the same thing? 
 
I have just purchased FastRawViewer I love its speed and features like focus peaking, not seen anything else like it.