redefine C-h

[YSK]

C-h is a normally prefix key, but I want to bind 'backward-char-
delete' to it. My .emacs has this:

(global-unset-key "\C-h")
(global-set-key "\C-\M-h" 'help-command)
(global-set-key [C-h] 'delete-backward-char)

I want to use C-M-h for help-command instead and use C-h for
backspace. However...it's not working. C-h remains a prefix key. My
understanding of prefix keys is basically nil, so there's probably
something pretty basic I'm missing here. Would anyone here be kind
enough to clue me in?

Thanks.