I have an unusual situation. My deployment environment needs to place pdftex and associated files into a custom directory that is not known until deploy time, and changes from one server to the next in a relatively random way. I.e. I cannot preinstall TEX on the server, and I cannot install anything into standard directories such as /etc, /usr/local, or the user's home directory. Everything needs to go into a custom directory like /path/to/deploy/here/somerandomstring.
Is there a way to make pdftex run such that it will look for files such as latex.fmt only in directories that I tell it to look in at runtime using some combination of command line arguments and environment variables?