I take it this means it cannot be done?
Actually it simply means that none replied to your thread.
It is possible that noone cares for your request of assistance, or that everyone is too busy right now, or that your request is seen somehow as irrelevant, or that the people that may know the matter didn't see the thread, who knows?
The only sure thing is that it can be done, since Easy2boot can do it, and since Easy2boot is essentially a (clever) set of menus and batch files making use of grub4dos functionalities, definitely it can be done.
Which is the difficult part in:
I know this may be possible with Easy2Boot but I am reluctant in using it because I'll have to change my whole file structure, curretnly being groupped into iso, img, flp etc.
Or if I have to Easy2Boot, could someone teach me how to use while still using my grub4dos version and menu.lst? I'd like to keep my current grub4dos menu.
You could explain to the OP how "your" way works, so that it can adapt it to his files structure...
Normally one would procure a spare USB device, use the Easy2boot to make sure that the method works, and then adapt it to the different files structure, AFAICT the real issue is making an actually valid, booting .dmg image, then what is used is little more than the "isohybrid" partnew approach originally by cdob:
and widely used since for Linux and other OS partitions images, of course adapted to the Mac OS image, Steve6375 has actually detailed how Easy2boot works specifically for these kind of images:
though from what I can understand, it seems like the whole thing is about Mac OS X installer (in a .dmg image), from your post it seems like you asked for a "live image"?
The "OSX_Installer_HFS_Boot.mnu" that you can find here:
is simple enough, it just maps the partition/volume image to (hdn,3) and chainloads its bootsector.