Handling large files differently?

Hi.. I am bumping up against limits with large H5P file sizes using WordPress to upload. In the shared hosting environment I am in, I am able to increase the timeout and filesize, but it is still not sufficient. My question is... if I can FTP my file into a directory where it can then be imported by the WordPress/H5P combo. For example, I can easily upload the large file to www.example.com/bigfiles/big.h5p ... bur then what? How can I slurp that file into the WordPress installation? Any thoughts on how to approach this? Thanks!