Write an Excel UDF (User Defined Function) that will allow a user to select a list of x, y coordinates, then select a set of facility coordinates, and then calculate the total of the minimum distances from each coordinate to all of the facilities. E. g. if there are 100 sets of x, y coordinates, and 4 four facilities, a user would first select the 100 x, y coordinates, then enter a comma and then select the 4 sets of x, y coordinates for the facilities. The UDF would then calculate the distance from each x, y coordinate to each facility, take the minimum of the four values, then add them all up.