[syslinux] modifying isolinux.cfg of a given, bootable iso

[Ian Brown]

Hello,
 I want to modify  isolinux.cfg of a given, bootable iso
(of Linux CentOs installation) according to my needs.
The things is :
I copy the contents of that iso to a different directory.
I modify the isolinux.cfg according to my needs.
Then what?
I had of course googled for it.
I had tried afterwards:
mkisofs -o centos1.iso -b isolinux/isolinux.bin -no-emul-boot
-boot-load-size 4 -boot-i
But the result is different:
Opening this new iso showed that all sunfolders are uppercase.
Moreover, there are files which look like:
BOOT.CAT;1
GPL.;1


what is the correct mkisofs command which I should issue in such a case?
Is there a way to retrieve the exact syntax of mkisofs with which that iso
was prepared (by some util like isoinfo)?

Regards,
IB