Adaptec used to have one... lemme see if I can dig it up... and if it WORKS under 2k/XP...
It's still part of the EZ CD Creator - it's called "Session Selector" and it can activate different sessions on the disc.
CD Roller, available at www.cdroller.com - seems to have a trial version, and includes a session selector.
Nero supposedly includes something called "Volume Mounter", that might be an older version of the multimounter you tried.
Badcopy Pro also includes a session selector.
ISO Buster also should do this.
Hope you own one of these... or want to get the eval or purchase. Do your own google for more.