Changing WMV Preview Thumbnails w/o re-rendering

[DVUser]

Is there a way to quickly (and without having to re-encode a WMV clip) insert a custom image (from a .jpg or .png) in place of the black intro Preview Thumbnails I have now on many of my Windows Media 10 video clips? I have several videos which have fade ins and I would like to insert a title that is only visible in the \My Videos video thumbnail setting.

Right now I have a bunch of black tiles which I'd like to replace with text and/or graphics with a JPG or PNG (title screens) - as one might replace an icon image for quick reference in a folder - and not have to open in Movie Maker, insert a still and then re-encode.

Thanks in advance for any feedback...

[bugster]

Can't be done, sorry