This is a repeated question; I've already replied to it many times.
If you already know how to use a boot floppy to make a bootable CD, and just don't know how to automatically switch to the CD drive letter after booting,
then you only need to solve the problem of finding the CD-ROM drive letter.
There are two methods:
1. Specify the CD-ROM drive letter: at the end of the line with MSCDEX.EXE in AUTOEXEC.BAT on the boot floppy, add /L:X (X can be replaced with another letter). Note that CONFIG.SYS should contain this line: LASTDRIVE=Z
This method is simple and easy to use; beginners are advised to use it.
2. Use FINDCD.EXE to find the CD-ROM drive letter. This method is a bit more complicated; you can refer to the Super Moderator's MSDOS7.10 super boot disk and PWIN98's boot disk.
After deciding which method to use, add one more line at the end of AUTOEXEC.BAT on the boot floppy:
X: (first method)
or
%CDROM%: (second method)
Then after booting, it will enter the CD-ROM drive letter (of course, the drive letter of the first CD-ROM drive).
You can test it with a floppy disk first, and burn the CD after it works.
If you still don't know how to use a boot floppy to make a bootable CD, then first look through the old posts, learn that, and then do the above.
After saying so much, if you still don't understand, then use the simplest method:
Use PWIN98's boot floppy, and add one line at the end of AUTOEXEC.BAT on the boot floppy:
%CDROM%:
Then use this boot floppy to make a bootable CD.