Access a CKEDITOR Instance from another window

Hi all,

I have one window that has 2 ckeditor instances, and from this windows a call a modal window. I´d like to know how to insert a text to the ckeditor instances from the modal window. I'm trying this way, but not has sucefull.

text = "abcdefg....";
var oEditor = CKEDITOR.instances[window.opener.document.forms[0]['tmp.relatorio_fundamentacao']];
oEditor.setData(text);

Someone can help me?

Thanks.
Luciano