Uploading Files to be Approved

Hey there… So I have a question that I’ve seen tossed around a bit but never answered straight..

How can I have it so someone can click on a “Click here to Upload” button, and then select a file off their computer, (And preferably I’d like to be able to limit what kinda files they could upload to just .rar files) once they upload the file, an admin on the website can view the uploaded file, and click an “approve or Deny” button, and be able to download the file.

This is a very specific request by my client, so I appreciate all help I can get!

Thanks
Kevin