This is gonna be kinda tricky and long, here goes...
To make the Mac portion of the CD:
Put your blank CD-RW into your Mac and put all the files you want on the CD on there and such. Then, open the window you want to open automatially when the CD is inserted. Place the window where you want it to be when the CD is inserted (middle of screen, whatever.) Whatever size, placement the window is now is how it's gonna look when you put the CD in later. Then, don't close that window, and burn the CD-RW. After the CD is burned, open up Toast and choose File->Save as Disc Image. You're gonna make an image of the CD-RW you just made.
To make the PC portion of the CD:
Since you're still in Toast, choose the Other tab, and pick ISO9660 (hopefully you have Toast Titanium!) Then add the files you want on the PC side. Now, here's the trickiest part. You need to make a file called autorun.inf, and add some lines to that file. You'll want to add something like this:
I'm pretty sure you can use relative directories here. You'll never really know the drive letter of the CD-ROM drive, so you can't hardcode a path to it. Another note, this is
case sensitive, even though DOS/Windows isn't. This was not a fun thing to learn the hard way! I'll check a CD I made and help you later about figuring out what exactly to put after open=.
To burn this sucker:
Burn what you've just done in the ISO9660 bit, but don't close the session. After that's burned, click the Other tab and choose Disc Image. Fine the disc image we made of the Mac CD and burn it. You can close the session this time if you like.