Frankell,
The solution was right under my nose. In Adobe Photoshop Elements I simply opened the .Gif animation and saved each layer as a separate .png file, each file representing an animation frame. From these (60) frames I used AniUtil.exe and et Voila, created the Animated Docklet complete with transparency as a 'Strip' image which is also used as the file icon.
So, for the benefit of anyone else watching this post, or who happens across it in the future, in summary:
- Only AniUtil.exe will create the Animated Shortcut
- AniUtil.exe will only accept frames exactly the same size
- Only AniUtil.exe will combine all the frames in the animation to create a single, horizontally regimented image ,which in turn will be used as the icon when viewing the .png file in Windows Explorer or other file manager.
- At run-time AniShortcut.dll will trigger the animation according to its configuration. ( unless of course you know different .......)
Thanks once again for everyone's contribution and help, with particular thanks to Frankell, who stayed with it! Virtual pints all round (I'd include a large whiskey (or chianti) but I can't find an appropriate Digi*Con).
Cheers everyone.

NB: Why StarDock don't support any other animation format is beyond my comprehension.