The Humax 9300T does not support this feature.
The utility humaxrw can read from the HDD of a 9300T if the Hard Disk Drive (HDD) is connected to a computer (.i.e. by first dismantling the 9300T) but it cannot yet write back to the 9300T. See http://humaxdisk.wikispaces.com/HumaxRW and http://myhumax.org/forum/topic/transfer-programs#post-20015.
If humaxrw were to be developed further to write to the HDD of a 9300T then you would also need to convert the film to a format the 9300T can handle (Mpeg-2 TS). Once converted you will need to use software ts2hre to generate the required hre side car. Ts2hdr comas as part of the humaxrw package.
Providing you can overcome both these obstacles you should also consider modifying the hardware on your 9300T so that you do not have to take the HDD out every time you want to transfer a converted film to the 9300T. See the following link for how to do this http://humaxdisk.wikispaces.com/9300T-9150T+mods.
humaxrw is currently not capable of writing to a 9300T HDD disk and therefore that is biggest obstacle you have.
NS
October 2013