Emmet VIM trigger key remap issue

Emmet VIM trigger key remap issue

I just installed Emmet VIM plugin which looks very interesting. The
"trigger key combination" to activate the Emmet plugin functionality is
not the best it could be. Therefore I am trying to remap it in my vimrc
file. I have successfully done that to remap the Escape key as follows:
inoremap ;; <ESC>
This allows me to type the semi-colon character ";" in rapid succession to
get out of the insert mode and get in the normal mode. However it does not
work when I try to remap the Emmet trigger key which is , (to be read as
Control key and "y" key, followed by the "," key). I have tried the
following combinations:
inoremap hh <C-y> ,
inoremap hh <C-y>,
inoremap hh <C-y,>
As you can see above, I am trying to map "hh" key combination to the Emmet
VIM's trigger keys.
Thanks in advance for your time.
Bharat