Thanks Lightening and dbminter for your fast responses.
lightening, I like the problem as a technical challenge. ImgBurn is a powerful program, and like your other users, I do want to use it. As for using downloaded ISOs, in my case that does not apply. I have edited HBCD to improve its functionality.
Dbminter, their are many program CDs which come with etfsBoot. There is no problem with ImageBurn collecting all the files, and using etfsBoot, making the ISO bootable. For the sake of discussion let us concentrate on a single utility CD, like Hiren HBCD. So how about a solution for making the ISO of HBCD as constituted from a bootable USB flash bootable ?