Yes, this is possible to do. You have to adapt the sector assignment which is done in LTE_common_calculate_cell_capacity. Currently the sector assignment is done based on the largest received power accounting for: transmit power, path loss, antenna gain, shadow fading. In our simulator, for the sector assignment, we only account in long term received power and not in RSRP which would also require to consider the microscopic losses (fast fading).
To plot a histogram, you just use the Matlab function histogram(data).