Thanx for you quick answer.
Yes I mean the dialog box that opens up when you talk to a NPC.
But I couldn't yet find any "offset"-option at the editors dialog setup page. My current editor version is 4.2.
I also tried you example, but unfortunately it "only" moved the 
area with the selectable sentences  to 0,0 fullscreen -  regardless what I put there, it won't move further 
down or right 

Another problem is that background graphics for the dialog box isn't affected by that command at all 

Is there a way to touch the dialog box background graphics via LUA ?