Ckeditor plugin development

I need a few ckeditor plugins. This project is a first of many, if you deliver good work you can build another ~20. Some require AJAX, others are really simple. But for now, I need this plugin: The plugin image should be a clock. When the button is pressed, a regular ckeditor popup should appear with two text fields with caption "time" and "format" (they both should just be input text fields without any requirements). When the user clicks "ok", it should insert this: [time($time)($format)] Where $time and $format are of course the input values. The editor should show the clock image instead of the text above (just like the hidden input field that is already available in ckeditor). With a little ckeditor experience this should be pretty straightforward. Remember: I need a lot more of these kind of plugins, and in the near future these should be expanded as well, so there is a probability this is long term.