I don't understand something.
By burning the iso to a cdrw (or extract the iso on hd with isobuster, for example), i will have 1100mb of data.
After adding my files, let's say 100mb (500 + 100 fits on a cd) i will have 1200 mb of data. It would be impossible to recreate the illegal toc for putting all the data on a CD R.
That's why i need to add these files to the iso, because i need to keep the illegal toc.