>Imagine the user just designed his screen and now he saved. No problem so far. The controls would be saved in a table >>(positions, sizes, formats, fonts, etc). But how can I save the relations between them? Z Order I mean.

ZOrder is current Controls/Objects index.

A start point ( with array )

* save
dimension aZorder[container.ControlCount]
for i=1 to ALEN(aZorder)
  aZorder[i]=container.controls[i].name
next
save(@aZorder)

* restore

dimension aZorder[1]
restore(@aZorder)

FOR i=1 to alen(aZorder)
  WITH getpem(container,aZorder[i])
     .ZOrder
  ENDWITH
NEXT