TOC describes tracks on a volume of a CD in the Lead-in area, q-subchannel (cf
ftp://ftp.ecma.ch/ecma-st/Ecma-130.pdf $22.3.4).
But you don't need to change the TOC to do what you want. You "only" need to change at least one File Descriptor (cf
ftp://ftp.ecma.ch/ecma-st/Ecma-119.pdf, $9).
If you have some skills in C/C++ (maybe it' possible in VB

), few hours to spent reading Ecma documentations, plus Micro$oft documentation (to do it with/without a driver, in adm mode), it's very simple : use EasyCD to extract the ISO file, use the program you made to modify the ISO file, then burn it (EasyCd again, but the file must be names .iso)
Anyway, it's a good scholar exercice : this kind of protection sheme is useless nowdays (BlindWrite, CloneCD). Of course, it can be the first step. If you're motivated enough, you can go after that to subchannel (p, q->w), or ATIP (remember ecma-130?), then finally try to figure out a maybe "good" protection sheme....
At least, you'll reached Safedisk and Securom, which is not so bad after all - but only if you do it during WE, of course. Otherwise, it doesn't count