If it's on the same account and server you want the new one on, and you paid for it, then just put the platinum in the shared bank, delete it and make a new one, but without the platinum. That should be in the shared bank though. If it's something different, like different account or server, then you won't have access to the original plat, and won't get new. Also, if this was created during the free, I'm not sure if you can still get a free one now or not. You'd have to ask some one more in the know.
EDIT: Also, this is assuming you created a HC, and didn't convert an existing character. You'd probably have to /petition to get the a converted toon, converted back and credited for a HC flag. I'd imagine deleting a converted HC would lose the flag. Again, not sure though. The FAQ may provide better answers at
https://www.everquest.com/news/heroic-character-faq Yther Ore.
Edited, Apr 26th 2014 3:05pm by Yther Edited, Apr 26th 2014 3:21pm by Yther