Insert filename without path into form field from popup?

I'm using a CKFinder popup to populate a form field with a file. I've got this working as needed, except for one thing. When I select a file/image and double click it, I get the following in the input field:

../../product/csfm/0328-0010.PDF

However, I only want this to be inserted:

0328-0010.PDF

Is this possible? Thanks for the help!