Here is a tough nut to crack: Clustering markers with exceptions

Hi, Iam looking for a way to cluster all my markers on google maps except of a few markers. These few markers may vary from time to time. Means for example: All markers contain an information like a number for instance. If the user watches the map of Europe all markers shall be clustered except of those 3 markers with the highest number. If the user moves to North America on the map or zooms out to see the whole world, all markers shall again be clustered except of the 3 markers containing the highest number.

Any idea is warmly appreciated. I assume this might not be possible .