Backup legally-owned Throne of Bhaal CD

Hi !
I'm french and bought french version of Throne of Bhaal ; I would like to backup my CD , but I have problems with the file named Area6500.bif . It seems impossible to copy it from the CD to the CD-R , and I already tried to install the entire BG2 game to ##### if I could find the file on my Hard Disk , but that failed . Did anybody meet the same problem ? Whenever my original CD gets lost or broken , would I be able to play TOB with a copy missing that damned Area6500.bif file ?
Thanks for answers !