Thanks, Steve and Randy, I think I played les than 25 minutes at this one in one session of a little bit more than one hour where I tried some different techniques. As the technique is discovered it is very fast to reproduce this kind of effects in Xara X.
I have some holidays next days and I will try to prepare a tutorial for Xara X main forum. I will post a link here when it will be ready.

Kind regards,

ivan