As today I saw a @binbinhfr question here:
I decide to post here this 2 following examples, which shows how to use GUICoordMode=2 + GUISetCoord()
Simple example:
#include <GUIConstantsEx.au3>
Example()
Func Example()
Opt("GUICoordMode", 2) ; relative to cell mode
GUICreate("My GUI Set Coord", 500, 200)
GUISetCoord(20, 50) ; move the current anchor position to a precise point (20,50)
GUIC