Allora qui:
<area shape=POLY coords="621,471,621,471,722,471,735,476,737,529,72 8,540,717,539,717,560,620,560,620,471,620,471,619, 472,621,471" href="http://abcdefg.it" alt="" OnMouseOut="window.status=''; return true" OnMouseOver="window.status=''; return true">

Aggiungi OnClick="windows.open(poi le istruzioni per il pop up )"