Question about cursor position in DIV

I want to implement this feature:

I add a div in FCKEditor, html code is below:

<div style="border-right: #cccccc 2px dotted; border-top: #cccccc 2px dotted; border-left: #cccccc 2px dotted; width: 300px; border-bottom: #cccccc 2px dotted; height: 300px" >AnyThing</div>

then I double click this div(any position), how to move cursor to the position I clicked at? or how to move cursor to the end of this div?

Thanks.