Based on the example .csv input file you attached, simply switch you nonzero positive integers from the wgr field to the bgr field. This will make DirectRT treat each set of trial rows with the same nonzero positive integers as single group of trials; just make sure that all of the rows with the same nonzero integer are contiguous in the .csv input file. DirectRT will randomize the presentation of these groups. Your use of the stimlists with $ will then randomly select items from the stimlists without replacement.