Hi,
there is already this topic, but still unanswered for last 14 years:
I have found an easy solution, but this strange forum allows me to create a new topic, but does not allow me to answer the old one.
I use the subst command in the Command Prompt like this:
C:\Users\Me>subst W: E:\Photos\
Now it is possible to build .iso file with "Preserve Full Pathnames" from the drive W: .
That's all!