I have a feeling that you could do this, but you would have to look at specific integration into the "Links" control provided by DNN, which is what we use in the documents module to handle access to the files.  This may be as simple as automatically placing the file in the directory and then using the "Automatically Sync File System" option in DNN.

Most likely you would then need to manually create the db entry for the document, but again it shouldn't be too complicated but as with ANY direct data manipulations you must be careful!