Sure, if you have a floppy image you can use dd.
However, the "ISO" comment worries me. I have never seen that file extension used for floppy images, usually ".img" or similar is used. Further, AFAIK, boot floppies use no ISO standard the way CDs use ISO9660. So, I assume the ISO is a CD-ROM image?
Anyways, tell us more about this "ISO" image you have and we can work this out. What is the full name of the ISO, where did you download it from, how large is it, etc.
I'm not saying this to be mean at all; I want to help. However, your post requesting help is typical of most people who want help: it doesn't give much detail. For anyone else reading this, giving way too much information is 100x better than not giving enough.