Splitting the database in matlab

I am work on neural network for finger vein authentication application. I'm going to use SDUMLA-HMT database which contain finger vein image of 106 individual of index, middle and ring finger images with 6 repetition for both hands. My Neural Network contains three input layer each of which going to deal the image of index, middle and ring finger images respectively. In this case how to split the database which feed the input to the three input layers with index, middle and ring finger respectively. whether i sholud to do it manually or is it possible to do it through code. Kindly let me know how to do it with code.

(Database contains two subfolders for left and right. In both left and ringht subfolders each having subfolders as 001,002,........,106 (106 individulas finger vein). Each subfolger contains index_1, index_2, ....index_6, middle_1, middle_2,.....,middle_6, ring_1, ring_2,....ring_6.)