I'd like to have a remote control interface with DDE or a similar fashion to send FRD new download links for integration with my browser. Is there a possibility to send the downloader programmatically new download links?

Try to connect computers with Teamviewer ( [teamviewer.com] ). It works perfectly including shared clipboard, captcha confirmation etc.
Download links copied in web browser of master computer are added to FRDownloader queue of slave computer.

DDE is "Dynamic Data Exchange", a local Windows protocol for exchanging commands between applications on a single computer. For more broader description see [en.wikipedia.org]. The successor of this is COM (in Windows).

TeamViewer and the likes has nothing to do with it and if a set of DDE commands would be implemented, this would make creating plugins for programmatically controlling FreeRapid a piece of cake, also integrating it shell scripts (and browser plugins of course). On OSX it's adding an AppleScript grammar and on Linux I guess it would be talking through a FIFO to FreeRapid.

It would suffice to have a grammar to add / remove downloads, asking for the list of current downloads and their statuses).