If I were you, I would not even bother with skin/physics weight. You MD guys are lucky to have such a great simulation engine inside your app.
And a lot of times it is not worth wasting time in iClone/CC with weights, where sometimes it is not even possible to achieve any decent outcome (specially on complex/odd cloth).
I have recently done some basic studying in bringing simulations from MD to iClone:
https://forum.reallusion.com/FindPost468229.aspx It is very much possible with very small exceptions.
One problem, is cloth interaction with objects other than the avatar. In most cases it is something to sit down on.
I've learned that you can bring an object into MD as another avatar and have it interact with garments.
Here is a skirt simulated in MD while girl is sittings down and then cloth alembic animation is brought to iClone.
In this case the simulation is basic and very easy achievable in iClone itself. But as I said, for something more complex it would be a nightmare.
The other problem is, that the animation has to be complete before exporting character to MD. But this is indeed a limitation and not much can be done.
Even a slight change in character animation would require complete new cycle for generating a new cloth simulation in MD.
It is also known, that Reallusion is planning to add an MD simulation import into iClone as a standard routine, which would make it even easier.
If you are still willing to go the cloth weights root, then you probably need to post screenshots of your item, or even better to post the item itself.
Mike or someone else would be happy to help if possible :)