Since maps v2 is deprecated, you are probably interested in v3 maps: https://developers.google.com/maps/documentation/javascript/markers#simple_icons
For v2 maps:
http://code.google.com/apis/maps/documentation/overlays.html#Icons_overview
You would have one set of logic do all the 'regular' pins, and another that does the 'special' pin(s) using the new marker defined.