I found something that might help...
MMD Have Riverdance motions which include these and many others;
https://www.youtube.com/watch?v=WysKZs83HHc ... which (apparently) can be converted to iClone motions, if you go through blender.
See Rampa's post for the workflow:
https://forum.reallusion.com/256992/A-better-Miku-Miku-Dance-PMDPMXVMD-Blender-plugin-Get-it-here ... which also contains links to other resources. Some have moved, but the new links for the updated pages are shown on the old pages.
And this post by Hirospot (about half way down this page) also has more information above MMD motions, which might also help.
https://forum.reallusion.com/128258/MikuMikuDance-anyone? I haven't had time to follow it all the way through yet.
But if you have luck and succeed, please let me know.
Note: By Coincidence, this is also being discussed in the German Forums with lots of interesting links and screenshots of motion adaptions from MMD (in addition to the above info, which is also discussed there),
so if you have a translation plug-in for your browser, then this link might help you too:
https://forum.reallusion.com/346190/Halloween-Town#bm346575
Anita, aka "Bleetz" the Toon Wrangler @ Tarampa Studios
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