Yes Sir, it is possible
When you build a tour - do not embedd xml files - then build a tour and find the xml file for the panorama with the video in a rectangle (suppose you have a virtual tour of a house and in one room there is a TV - you find this TV click on the screen - and you want it to start playing a video only after you clicked on it) So find an xml for the panorama with this TV (i.e. a video in a rectangle) open this xml with a notepad or Dreamweaver or Notepad++(a good program for this purpose)
Find the code for your rectangle video - it would look like that

<hotspot name="spot3" handcursor="false" url="testdata/graphics/videoplayer.swf" videourl="testdata/graphics/spots/spot1.flv" onclick="closeglobalobjects();togglepause()" distorted="true" ath="50.032" atv="-24.6507" width="244" height="185" rx="-29.8628" ry="31.1294" rz="0.811296"/>

(this paragraph is optional - you may skip it)
If you decode this it means  1) "spot3" - this is the 4th hotspot you added to panorama (in my example it was the 4th) as there is also a hotspot0. 2)  handcursor="false" means that when you move your mouse over the rectange it would turn into a handcursor (in this example it won't as it is set to false) 3) url="testdata/graphics/videoplayer.swf" - this is the path to the videoplayer that would start the video 5) videourl="testdata/graphics/spots/spot1.flv" - this is the path to the video file 6) onclick option defines the actions done when you click on this object (you've got pausetoggle here) 7) distorted="true" is used only for object inside rectangles and means that when you move the panorama this object would distort approaching to the edges of you screen.  Other parameters defines vertical and horizontal displacement and the coordinates of your rectangle.


So basically you need to change handcursor="false" to handcursor="true" and add one line before the onclick option and this line is      pausedonstart="true"

When you have done this changes the code will look like this

<hotspot name="spot3" handcursor="true" url="testdata/graphics/videoplayer.swf" videourl="testdata/graphics/spots/spot1.flv" pausedonstart="true" onclick="closeglobalobjects();togglepause()" distorted="true" ath="50.032" atv="-24.6507" width="244" height="185" rx="-29.8628" ry="31.1294" rz="0.811296"/>

Yeeahhh!!!! really really really... Thank you Gund!!! a thousand thanks!