How can I get a parent GUI coordinates?

[MCP]

I have a function that creates a gui that I would like to have it centered on top of its parent window.

I do not know wich action is needed to retrieve the coordinates of a window I have created.

_WinAPI_SetParent(), _WinAPI_SetWindowPos(), GUICtrlSetPos() is all of what I have looked at, but

no instruction seems to fit the case.

Isn't there anything sounding like GUIGetCoord($hWnd) / GUISetCoord($i_X, $i_Y) ?

[Generator]

Retrieves the position and size of a given window.

WinGetPos ( "title" [, "text"] )