Change htaccess deny from all

Hi, I need some help to solve this problem:
If the system (wpfd) uploads a file it creates a .htaccess with deny from all.
I have installed a pdf compressor and now I need to whitelist ip's to get access to the pdf-files without restrictions.

Is there a way I can tell wpfd that some server (in that case our shop which is a different server and we link files from our shop to the wordpress site PDF-Files managed by wpfd) are whitelisted?

this would be awesome
thx. and best RW