how to make clustering based on distance?

hi, i am working on clustering in matlab. firstly, i need to calculate the distance between the cluster head and other random points. then, when i calculated their distance, i will have to cluster them base on the minimum distance.

for example, my cluster head is (10,20) and (16,24), and other random points such as (12,18),(15,15), (13,20) and (14,22). then i will have to calculate the distance between the cluster head and the other random points, and do clustering based on the minimum distance obtained between cluster head and the random points. how should i make the code to determine that it should belong to that cluster?