The problem you are encountering is a common one when using a double mesh system. This happens often when using programs like Poser and attaching clothing to figures. CloneCloth does an excellent job of avoiding this problem but sometimes it is unavoidable.
There is no quick fix sadly but you could try using the same method that is used to stop the legs showing through the CloneCloth dresses. Take a look at the link below and see if this can help your problem.
http://www.reallusion.com/ContentStore/iClone/pack/CloneCloth/Skirt_help.htm
You could also try using a different hand pose and see if that reduces the effect.
Peter EdwardsForum Moderator
iClone Daily Blog