Unwrap Editor Window: setWindowXOffset not working -_-

in the 3dsmax 2009 help it says:

<void><Unwrap_UVW>.setWindowXOffset <integer>offset

Sets the horizontal window offset.
Exposed via unwrap5 interface in 3ds Max 8 and higher.

basicly the same for r9 online

i tried:
selection[1].modifiers[#unwrap_uvw].unwrap5.setWindowXOffset 64;
with 1 object selected and the uv-editor window opened but nothing happens !?!

just on a sidenote:
the command GetWindowW apperently is exposed via unwrap2 interface but thats plain wrong as I found out because its called like this:
so I am wondering if this command setWindowXOffset is even supported at all?

what I want in the end is to adjust the UV-editor window position so that it gets placed next to my custom uv-tools floater:

if anyone could help me with this or knows something (because I cant google anything about it) that would be nice