Automatic file rename

Hi all
I’m using RW 6.3 with TeslaPro Theme. As my old Webcam is gone I bought a new D-Link. Unfortunately the Cam sends the pics always with an new name e.g. Picture1439444715_2125.jpg, Picture1439441115_1756.jpg and so on.
I’d like to automatically rename this file to Picture.jpg so the I can embed it on my site.

Is there a solution in RW or has this to be done “outside” on the web server?

I have no programming knowledge so I would need to have an Script example to solve my problem.

Thanks for help