Finally I had some time to do this
First dropbox is a file sync software, that sync yours local files in a " cloud " type off webdir.
I use this to sync my software.
Because the software is in a " cloud " i want people to be able to download this software and keep track off num downloads, and limit this to registered users.
I have made change's to com_download in order to do this.
since i am the only one how can put downloads on my site, i only needed to adapt the form in the backend.
and change the front end working's.
file's changed are
For those how want to use or check this for faults
have attached the changed installer file's
let me know what you think ( i'm not a php programmer)