add-on creation and installation in suse linux

Hi, i have downloaded a new kernel version(4.14) and built with Suse Linux, so kernel.rpm files gets generated. But i want to repack this newly built kernel with existing suse-linux.iso image. So, for this purpose i am using Mksusecd command :-

" sudo mksusecd --create new_ker.iso --addon kernel-4.14.175_94.41_default.x86_64.rpm – SLE-12-SP4-Desktop-DVD-x86_64-GM-DVD1.iso ".

This command is creating a image file which has a new kernel as an add-on. While installation it is showing added add-on but it is not installing the new kernel . Installation proceeded with Old existing kernel in iso image.

Can anyone guide me how i can add a newly built kernel to the existing ISO image file so that i can install the new built kernel during the installation process of Suse-linux.