If the temporary files are placed in a specific folder (I don't have DVDFab to check), you may be able to reallocate it by replacing that folder with a directory junction.
From the command line, it's:
mklink /j [Directory] [Target]
For example, let's say I want to move "C:\Users\Sean\AppData\Local\Mozilla" to "H:\Mozilla", first I would move the Mozilla folder to the H drive and then enter the command:
mklink /j "C:\Users\Sean\AppData\Local\Mozilla" "H:\Mozilla"
To any Mozilla product, it would appear as if the folder was still in "C:\Users\Sean\AppData\Local\", but in reality anything it reads/writes in that path is diverted to "H:\Mozilla". Similarly in Windows Explorer, the folder contents can be browsed, also giving the impression that it's still on the C drive.