Codez un logiciel

I would like to code a little application that will give me the best location for a meeting between a defined list of locations dependinf of where the participants of this meeting work 1. I will provide a list (excel) of 1300 persons and their location 2. I will provide a list of more or less 20 locations (cities) where a meeting can be hold --) the outcome will be be, an IT field where i select the persons invited to a meeting. An algortithm need to défine which are the 3 best locations to held the meeting (average less km) with 1rst choice, second and third choice and the averga nb of km for each to reach it