A. When Outlook opens a PST file it needs write access so you will be unable to load a file from a read-only media such as a CD-ROM drive.
To resolve simply copy the file to a writeable media and read accordingly.
Messages can be send to a .pst file by using Outlooks archive function. To open with Outlook 98 select File - Open - Personal Folders File.
If you store the PST files in a ZIP file on a CD they can be accessed (as when you access a ZIP file it is decompressed locally which would be writable).