Insert html from from window

I have now tried several things, but i need some help.

I have made a new plugin that calls a window like this:

CKEDITOR.plugins.add('specialcode',
{
init: function(editor)
{
var pluginName = 'specialcode';
editor.ui.addButton('specialcode',
{
label: 'specialcode',
command: pluginName,
icon: this.path + 'myplugin.png',
click: function (editor) { window.open('/specialcode.asp','Image Browser','width=900,height=600'); }
});
}
});

This is working fine.

The windows opens and here i have several div tags.
Each div tag contains different HTML code, and when i click a div tag, the content must be put into the editor, but how can i get the content from a div tag insert into the editor with InsertHTML?

It's important that i can get the content form my ASP document because it is generated from a database.

I'm new to CKeditor, but in the Innovastudio editor, i used something like this:

<script>
function insertObject(sHTML)
{
var obj=(opener?opener:openerWin).oUtil.obj;
obj.insertHTML(sHTML);
}
</script>

<div onClick="insertObject(document.getElementById('div1').innerHTML);self.close();">Click to insert form</div>

<div id="div1" style="display:none">This is the content that i insert into the editor</div>