Is it possible to automatically insert a field name into a photo's filename on upload?

Hello! 

Is it possible to get a field name inserted into a file name of a photo when it's uploaded?

For example: clients entering photos such as  "img_2259.jpg", "horsepic23.jpg"

Could a field such as "name" or "num" be automatically added to result in the following: charlie-img_2259.jpg  or 101-horsepic23.jpg

If it makes any difference, the images would not necessarily need to be used on the website - just stored to the server and used later as high-res copies for use & reference when converting the database content to a printed catalog. We've maintained the original upload image and only used resized thumbnails throughout the website. 

I've been doing this manually but thought their might be an easier way. 

Thanks! Tina