I assume you're using DOSBox because you mention "mounting."
You also have to mount the CD drive.
Check here for information on how to mount
http://www.dosbox.com/wiki/MOUNTExample: if your CD drive is F:, mount it this way:
Z:\>MOUNT D F:\ -t cdrom
The game in DOSBox will recognize your CD drive as D: even though the drive name in Windows is F:
Once everything is mounted properly, you can list the contents of the drive in DOSBox using the command DIR D:
According to the manual, you install the game by entering
D:\INSTALL