I don't know for sure, but I know that after a couple days trying to do something similar I just couldn't figure it out.
My reason was to try and use an XP upgrade (with my original Win98 CD). Since boot camp won't let you eject, there was no way to do this on the boot camp partition, although I could under VMware.
I almost gave up on boot camp, until I learned I could slipstream the upgrade with a Win98 folder.
Why can't you just use boot camp to install and then run from the boot camp partition?