Можно снимать координаты мыши со страницы через каллбак. Немного подпилим пример из хэлпа.
флэш:

Код AS1/AS2:
import flash.external.ExternalInterface;
ExternalInterface.addCallback('moveEye',this,moveEye);
function moveEye(x,y){
out.text = arg;
eye_mc._x = x;
eye_mc._y = y;
}
хтмл:

Код:
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<script language="JavaScript">
function onMouse() {
getMovieName("Untitled-1").moveEye(event.x/10, event.y/10);
}
function getMovieName(movieName) {
if (navigator.appName.indexOf("Microsoft") != -1) {
return window[movieName]
}
else {
return document[movieName]
}
}
</script>
<meta http-equiv="Content-Type" content="text/html; charset=koi8-r" />
<title>Untitled-1</title>
</head>
<body onmousemove="onMouse()" bgcolor="#ffffff">
<!--url's used in the movie-->
<!--text used in the movie-->
<!-- saved from url=(0013)about:internet -->
<object classid="clsid:d27cdb6e-ae6d-11cf-96b8-444553540000" codebase="http://fpdownload.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=8,0,0,0" width="550" height="400" id="Untitled-1" align="middle">
<param name="allowScriptAccess" value="sameDomain" />
<param name="movie" value="Untitled-1.swf" /><param name="quality" value="high" /><param name="bgcolor" value="#ffffff" /><embed src="Untitled-1.swf" quality="high" bgcolor="#ffffff" width="550" height="400" name="Untitled-1" align="middle" allowScriptAccess="always" type="application/x-shockwave-flash" pluginspage="http://www.macromedia.com/go/getflashplayer" />
</object>
</body>
</html>