Replace the default image dialog

We have our own way of uploading images contained in a snippet of html. So what we want to do is to have the FCKEditor bring up an image dialog that lets the user pick a file from their machine. Then the dialog should just insert the image tag into the FCKEditor using the local file path for the image. The current 4 tabbed dialog is not very useful to us and we would like to remove it. Is this very difficult to do (is there a flag or something that just show a generic image picker?) I'd hate to have to change the base FCKEditor code, because we want to keep up with the latest releases.