2003 XP Pro up to date

Would like to process a batch file to run a series of programs and/or
copy/delete command lines.

Also, would like to have the 1) copy/paste files and 2) the batch
file(s) on a Read-only DVD.

Once I start the batch file, how can I detect the drive letter of the
respective user's CD/DVD drive and carry that variable through
subsequent batch file command lines. (Keep in mind, that my CD is Read
Only)

TIA

EagleOne